Resist underlayer material, pattern formation method, and resist underlayer formation method

Abstract

To provide a resist underlayer film material capable of forming a resist underlayer film with excellent planarizing properties and film formability, while also delivering a resist underlayer film with appropriate etching characteristics.SOLUTION: A resist underlayer film material includes: (A) a compound containing no phenolic hydroxyl groups, or a compound having phenolic hydroxyl groups modified and in which the residual rate of the phenolic hydroxyl groups is less than 2%, wherein the compound has a weight average molecular weight of 2,500 or less in terms of polystyrene by gel permeation chromatography; (B) a crosslinking agent containing a phenolic hydroxyl group represented by the general formula (1); (C) a base generator; and (D) an organic solvent.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a resist underlayer material that can be used for fine patterning by a multilayer resist method in the semiconductor device manufacturing process, a pattern formation method using the material, and a resist underlayer formation method. [Background technology]

[0002] With the increasing integration and speed of LSIs, the miniaturization of pattern dimensions is progressing rapidly. Lithography technology has achieved the formation of fine patterns in line with this miniaturization by shortening the wavelength of the light source and appropriately selecting the resist composition. At the heart of this is the single-layer positive photoresist composition. This single-layer positive photoresist composition has a framework in the resist resin that is resistant to dry etching with chlorine-based or fluorine-based gas plasma, and also has a switching mechanism that causes the exposed area to dissolve, thereby forming a pattern by dissolving the exposed area, and the remaining resist pattern is used as an etching mask to dry etch the substrate to be processed.

[0003] However, when the thickness of the photoresist film used was kept the same while miniaturization was achieved, i.e., the pattern width was reduced, the resolution performance of the photoresist film decreased. Furthermore, when attempting to develop the photoresist film using a developer, the aspect ratio became too large, resulting in pattern collapse. For this reason, as patterns became smaller, the photoresist film was made thinner.

[0004] On the other hand, the processing of substrates typically involves using a photoresist film with a pattern formed on it as an etching mask and processing the substrate 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. As a result, the resist film is damaged and disintegrates during substrate processing, making it impossible to accurately transfer the resist pattern to the substrate. Therefore, with the miniaturization of patterns, higher dry etching resistance has been required for resist compositions. However, at the same time, in order to improve resolution, resins with low light absorption at the exposure wavelength have been required for the resins used in photoresist compositions. Therefore, as the exposure light has become shorter in wavelength, from i-line to KrF and ArF, the resins have also changed to novolac resins, polyhydroxystyrene, and resins with aliphatic polycyclic skeletons. However, in reality, the etching rate under dry etching conditions during substrate processing has become fast, and recent photoresist compositions with high resolution tend to have weaker etching resistance.

[0005] This necessitates dry etching of the substrate using a thinner photoresist film with weaker etching resistance, making the securing of materials and processes for this manufacturing step crucial.

[0006] One way to solve these problems is through the multilayer resist method. In this method, a photoresist film (i.e., a resist upper layer) and an intermediate film with different etching selectivity are interposed between the resist upper layer and the substrate to be processed. After obtaining a pattern on the resist upper layer, the resist upper layer pattern is used as a dry etching mask to transfer the pattern to the intermediate film by dry etching, and then the intermediate film is used as a dry etching mask to transfer the pattern to the substrate to be processed by dry etching.

[0007] One multilayer resist method is the three-layer resist method, which can be performed using the same resist compositions as those used in the single-layer resist method. In this three-layer resist method, for example, an organic film made of novolac resin or the like is deposited on the substrate to be processed as the resist underlayer, a silicon-containing film is deposited on top of that as the resist interlayer, and a normal organic photoresist film is formed on top of that as the resist upper layer. When dry etching is performed using a fluorine-based gas plasma, the organic resist upper layer has a good etching selectivity ratio compared to the silicon-containing resist interlayer, so the resist upper layer pattern can be transferred to the silicon-containing resist interlayer by dry etching with a fluorine-based gas plasma. With this method, even if a resist composition that does not have sufficient thickness to form a pattern for direct processing of the substrate or a resist composition that does not have sufficient dry etching resistance for substrate processing is used, the pattern can be transferred to the silicon-containing film (resist interlayer), and then by performing pattern transfer by dry etching with an oxygen-based or hydrogen-based gas plasma, a pattern of an organic film (resist underlayer) made of novolac resin or the like with sufficient dry etching resistance for substrate processing can be obtained. Many types of resist underlayer films, such as those described in Patent Document 1, are already known.

[0008] In recent years, there has been increased activity in the development of new semiconductor devices with structures such as multi-gate structures. In response to this, there is a growing demand for resist underlayer films with superior planarization and filling characteristics compared to conventional films. For example, when the underlying substrate has minute pattern structures such as holes, trenches, or fins, the resist underlayer film needs to be able to completely fill the gaps within the patterns with the film. Also, when the underlying substrate has steps or when densely patterned areas and areas without patterns exist on the same wafer, the resist underlayer film needs to planarize the film surface. By planarizing the underlayer film surface, variations in the film thickness of the resist interlayer and resist upper layer deposited on top can be suppressed, thereby reducing the focus margin in lithography and the margin in subsequent processing steps of the substrate.

[0009] Furthermore, organic film materials with excellent embedding / planarization properties are not limited to underlayer films for multilayer resists, but can also be widely applied as planarization materials for semiconductor device manufacturing, such as substrate planarization prior to patterning by nanoimprinting. In addition, while the CMP process is currently commonly used for global planarization in semiconductor device manufacturing, CMP is a high-cost process, and these materials are expected to serve as an alternative global planarization method.

[0010] To form a planarization film for flattening uneven semiconductor substrates, a resist underlayer material containing a low-viscosity, high-thermal-fluidity compound has been proposed (Patent Document 2). However, this material has the problem that, for example, its wettability to hydrophobic substrates treated with hexamethyldisilazane (hereinafter referred to as HMDS) is significantly reduced, making it prone to pinholes and film edge recession. Furthermore, in state-of-the-art devices, the resist underlayer is also becoming thinner due to the thinning of the resist upper layer as a result of pattern miniaturization, making it even more difficult to ensure wettability. Improving the adhesion to the substrate is effective in improving the wettability of the underlayer material, and a resist underlayer material having an amide structure as a component of polar functional groups has been proposed (Patent Document 3). However, although this resist underlayer material has good wettability and planarity on silicon substrates, its wettability to hydrophobic substrates is insufficient. Thus, there is a need for an underlayer material that achieves both excellent planarization characteristics, wettability to hydrophobic substrates, and sufficient etching resistance, as well as a pattern formation method using the same.

[0011] Furthermore, as mentioned above, the structure of the substrates to be processed is becoming more complex, and new materials with high electron mobility, such as strained silicon and gallium arsenide, as well as ultrathin polysilicon films controlled in angstroms, are also being considered for the surface of the substrates to be processed. It is anticipated that films will be deposited on a wide variety of substrate surface shapes and materials. Therefore, in order to ensure process margins, not only excellent planarization characteristics but also the ability to deposit films regardless of the material and shape of the substrate is an important characteristic. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2004-205685 [Patent Document 2] Japanese Patent Publication No. 2017-119670 [Patent Document 3] Japanese Patent Publication No. 2021-196467 [Overview of the project] [Problems that the invention aims to solve]

[0013] The present invention has been made in view of the above circumstances, and aims to provide a resist underlayer material that can form a resist underlayer film with excellent flatness and film-forming properties, even on a workpiece substrate having particularly difficult-to-planar parts such as wide trench structures in a fine patterning process using a multilayer resist method in semiconductor device manufacturing processes, and that provides a resist underlayer film with appropriate etching properties, as well as a pattern formation method and a resist underlayer film formation method using the same material. [Means for solving the problem]

[0014] In order to solve the above problems, the present invention provides: (A) Compounds that do not contain phenolic hydroxyl groups, or compounds that are modified with phenolic hydroxyl groups and have a residual rate of less than 2% of the phenolic hydroxyl groups, wherein the polystyrene-based weight-average molecular weight of the compound determined by gel permeation chromatography is 2,500 or less. (B) A crosslinking agent containing a phenolic hydroxyl group represented by the following general formula (1), (C) Base generator, and (D) Organic solvents The present invention provides a resist underlayer material that contains the following: [ka] (In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. 16 (where is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; q is an integer from 1 to 5.)

[0015] For such a resist underlayer film material, in a fine patterning process using a multilayer resist method, it is possible to form a resist underlayer film excellent in flatness and film-forming property even on a substrate to be processed having a portion difficult to planarize. This underlayer film further has appropriate etching characteristics. For example, it is possible to form a resist underlayer film excellent in film-forming property on a hydrophobic substrate treated with HMDS.

[0016] Further, it is preferable that the (C) base generator is a compound that exhibits basicity by thermal decomposition.

[0017] For such a resist underlayer film material, it is assumed that the film-forming property is excellent because the phenolic hydroxyl group of the crosslinking agent becomes ionic and the interaction with the substrate increases during film baking. By adjusting the addition amount, it is possible to achieve both thermal fluidity and interaction with the substrate.

[0018] Furthermore, it is preferable that the (C) base generator is any one of those represented by the following general formulas (2), (3), and (4). [Chemical formula] (In the above formula, R 01 ~R 03 each independently represents a linear, branched or cyclic alkyl group or alkenyl group having 1 to 10 carbon atoms which may be substituted with a hetero atom or may have a hetero atom intervening, or an aryl group or aralkyl group having 6 to 18 carbon atoms which may be substituted with a hetero atom or may have a hetero atom intervening. Also, any two of R[[ID=2X]] 01 、R 02 and R 03 may be bonded to each other to form a ring together with the sulfur atom in the formula. X - represents an organic or inorganic anion serving as a counter ion. However, X - does not contain OH - . R 04 and R 05Each of these is an aryl group having 6 to 20 carbon atoms, which may be independently substituted with a heteroatom or may have a heteroatom interposed therein, and some or all of its hydrogen atoms may be substituted with a linear, branched, or cyclic alkyl or alkoxy group having 1 to 10 carbon atoms. Also, R 04 and R 05 These atoms may bond to each other to form a ring with the iodine atom in the formula. 06 , R 07 , R 08 and R 09 Each independently represents a linear, branched, or cyclic alkyl, alkenyl, or aralkyl group having 1 to 20 carbon atoms, which may be substituted with a hydrogen atom or a heteroatom, or which may have a heteroatom interposed; or an aryl or aralkyl group having 6 to 18 carbon atoms, which may be substituted with a heteroatom, or which may have a heteroatom interposed. Also, R 06 , R 07 , R 08 and R 09 Two or more of these may bond with each other to form a ring with the nitrogen atom in the formula.

[0019] Furthermore, X in the general formulas (2), (3), and (4) - However, it is more preferable that the structure is represented by any of the following general formulas (5), (6), and (7), and that it is one of the anions selected from the group consisting of chloride ions, bromide ions, iodide ions, fluoride ions, cyanide ions, nitrate ions, and nitrite ions. [ka] (In the above formula, R 10 R represents a linear, branched, or cyclic alkyl, alkenyl, aralkyl, or aryl group having 1 to 20 carbon atoms, which may include an ether group, ester group, or carbonyl group, and the hydrogen atoms of these groups may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. 11R represents an aryl group having 1 to 20 carbon atoms. The hydrogen atoms of the aryl group may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. 12 , R 13 , R 14 Each of these independently represents a hydrogen atom, a halogen atom other than a fluorine atom, or a linear, branched, or cyclic alkyl, alkenyl, aralkyl, or aryl group having 1 to 20 carbon atoms, which may also contain an ether group, an ester group, or a carbonyl group, and the hydrogen atoms of these groups may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. 12 , R 13 , R 14 Two or more of these may be bonded together to form a ring.

[0020] Furthermore, X in the general formulas (2), (3), and (4) - It is preferable that the boiling point of the conjugate acid XH is 200°C or lower.

[0021] By appropriately selecting a base generator (thermal base generator) that exhibits basicity through such thermal decomposition, it is possible to induce basicity in accordance with the firing temperature of the resist underlayer material, thereby achieving both film formation and flatness. Furthermore, since the entire amount decomposes or evaporates during firing and does not remain in the film after firing, it does not adversely affect performance other than film formation.

[0022] Furthermore, it is preferable that the compound (A) is represented by the following general formula (8). [ka] (In the formula, W is an n-valent organic group having 2 to 50 carbon atoms. n is an integer from 2 to 10, and Y is independently one of the structures shown in the general formula (9) below.) [ka] (In the formula, the dashed line represents the bond site to W. Z is one or more terminal groups, and at least one of the terminal groups is one of the groups shown in the following general formula (10).) [ka] (In the equation, dashed lines represent connections.)

[0023] With such a resist underlayer material, it is possible to form a resist underlayer with excellent flatness and film-forming properties, even on a substrate that has particularly difficult-to-planar areas, such as a wide trench structure.

[0024] Furthermore, in this case, Z in the general formula (9) can be a compound composed of one or more of the groups represented by the general formula (10) and one or more of the groups represented by the following general formulas (11) and (12). [ka] (R in equation (11) above) p R represents a linear, branched, saturated, or unsaturated hydrocarbon group having 1 to 30 carbon atoms, which may be substituted with heteroatoms or may have heteroatoms interposed. q R represents a hydrogen atom or a linear, branched, saturated, or unsaturated hydrocarbon group having 1 to 10 carbon atoms. r The terms represent linear or branched hydrocarbon groups, halogen atoms, nitro groups, amino groups, nitrile groups, alkoxycarbonyl groups, and alkanoyloxy groups with 1 to 10 carbon atoms. m1 represents 0 to 2, m2 and m3 represent the number of substituents on the aromatic ring, m2 and m3 represent integers from 0 to 7, and m2 + m3 satisfies the relationship between 0 and 7. If a is the proportion of the structure of general formula (10) constituting Z, and b is the proportion of the total structure of general formulas (11) and (12), then the relationships a + b = 1.0, 0.50 ≤ a ≤ 0.99, and 0.01 ≤ b ≤ 0.50 are satisfied.

[0025] Such resist underlayer materials possess sufficient curability, and by combining aromatic ring structures and hydrocarbon end group structures, various physical properties such as heat resistance, etching resistance, embedding / planarization characteristics, adhesion to the substrate, and control of optical constants can be adjusted and improved according to the required performance.

[0026] Furthermore, it is preferable that W in the general formula (8) is a structure represented by one of the following formulas. [ka] [ka] (In the equation, dashed lines represent connections.)

[0027] Such a resist underlayer material can form a resist underlayer with excellent film-forming properties and flatness, and is particularly easy to manufacture.

[0028] Preferably, the (D) organic solvent is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher.

[0029] With such a resist underlayer material, the flatness of the formed resist underlayer can be further improved, regardless of the design of the substrate being processed, such as the density of the pattern.

[0030] Furthermore, the resist underlayer material of the present invention may contain one or more of (E) surfactants, (F) plasticizers, and (G) dyes.

[0031] Thus, the resist underlayer material of the present invention may also be supplemented with (E) a surfactant to improve the coatability in spin coating, (F) a plasticizer to further improve the embedding / planarization properties, and (G) a dye to adjust the absorbance properties. By adding or selecting these various additives, it is possible to fine-tune the performance according to requirements, such as film formation properties, curability, embedding properties, and optical properties, which is practically preferable.

[0032] Furthermore, the present invention is A method for forming a pattern on a substrate to be processed, (I-1) A step of forming a resist underlayer film by applying the above resist underlayer film material onto a substrate to be processed and then heat-treating it. (I-2) A step of forming a resist upper layer film on the resist lower layer film using a photoresist material, (I-3) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (I-4) A step of transferring the pattern to the resist underlayer by dry etching using the resist upper layer on which the pattern is formed as a mask, and (I-5) A step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed, The present invention provides a pattern forming method having the following characteristics.

[0033] Furthermore, the present invention is A method for forming a pattern on a substrate to be processed, (II-1) A step of forming a resist underlayer film by applying the above resist underlayer film material onto a substrate to be processed and then heat-treating it. (II-2) A step of forming a resist interlayer on the resist underlayer, (II-3) A step of forming a resist upper layer film on the resist interlayer film using a photoresist material, (II-4) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (II-5) A step of transferring the pattern to the resist interlayer by dry etching, using the resist upper layer on which the pattern is formed as a mask. (II-6) A step of transferring the pattern to the resist underlayer film by dry etching, using the resist interlayer film on which the pattern has been transferred as a mask, and (II-7) A step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed, The present invention provides a pattern forming method having the following characteristics.

[0034] Furthermore, the present invention is A method for forming a pattern on a substrate to be processed, (III-1) A step of forming a resist underlayer film by applying the above resist underlayer film material onto a substrate to be processed and then heat-treating it. (III-2) A step of forming an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the resist underlayer film, (III-3) A step of forming an organic thin film on the inorganic hard mask interlayer, (III-4) A step of forming a resist upper layer film on the organic thin film using a photoresist material, (III-5) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (III-6) A step of transferring the pattern to the organic thin film and the inorganic hard mask interlayer film by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (III-7) A step of transferring the pattern to the resist underlayer film by dry etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask, and (III-8) A step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed, The present invention provides a pattern forming method having the following characteristics.

[0035] Thus, the resist underlayer material of the present invention can be suitably used in various pattern formation methods, such as a two-layer resist process, a three-layer resist process using a resist interlayer, and a four-layer resist process using an organic thin film in addition to these. With these pattern formation methods, the formation of the resist underlayer effectively reduces unevenness and steps in the substrate to be processed, making it suitable for photolithography of the resist upper layer.

[0036] Furthermore, in the pattern formation method of the present invention, the inorganic hard mask interlayer can be formed by CVD or ALD.

[0037] In the pattern formation method of the present invention, it is possible to combine an inorganic hard mask interlayer formed by CVD or ALD with a resist underlayer formed by spin coating.

[0038] Furthermore, in the pattern formation method of the present invention, it is possible to use a substrate with a structure or step of 30 nm or more in height as the substrate to be processed.

[0039] Furthermore, in the pattern forming method of the present invention, it is possible to use a substrate with a static contact angle with water of 50° or more as the substrate to be processed.

[0040] The resist underlayer material of the present invention is particularly useful for microfabrication of substrates having structures or steps, as it exhibits excellent embedding / planarization characteristics and film formation properties on hydrophobic substrates.

[0041] Furthermore, the present invention is The present invention provides a method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of semiconductor devices, comprising: rotating and coating a resist underlayer film material onto a substrate to be processed; and heat-treating the substrate coated with the resist underlayer film material at a temperature of 100°C to 600°C for a range of 10 to 600 seconds to cure and form a resist underlayer film.

[0042] Furthermore, the present invention is The present invention provides a method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of semiconductor devices, comprising: rotating and coating a resist underlayer film material onto a substrate to be processed; and heat-treating the substrate coated with the resist underlayer film material in an atmosphere with an oxygen concentration of 1% by volume or more and 21% by volume or less to cure and form a resist underlayer film.

[0043] This method promotes the crosslinking reaction during the formation of the resist underlayer film and more effectively suppresses mixing with the upper layer film. Furthermore, by appropriately adjusting the heat treatment temperature, time, and oxygen concentration within the above range, suitable embedding / planarization and curing characteristics of the resist underlayer film can be obtained for the intended application.

[0044] Furthermore, the present invention is The present invention provides a method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of semiconductor devices, comprising: rotating and coating a resist underlayer film material onto a substrate to be processed; and curing the substrate coated with the resist underlayer film material by heat treatment in an atmosphere with an oxygen concentration of less than 1 volume% to form a resist underlayer film.

[0045] This method is useful because, even when the substrate to be processed contains materials that are unstable when heated in an oxygen atmosphere, it promotes the crosslinking reaction during the formation of the resist underlayer film without causing degradation of the substrate, and more effectively suppresses mixing with the upper layer film.

[0046] Furthermore, the substrate to be processed can be a substrate with a structure or step of 30 nm or more in height.

[0047] Furthermore, a substrate with a static contact angle of 50° or more with respect to water can be used as the substrate to be processed.

[0048] The resist underlayer film formation method of the present invention uses a resist underlayer film material of the present invention that can form a resist underlayer film with excellent embedding / planarization characteristics and film formation properties on hydrophobic substrates, and is therefore particularly suitable for forming a resist underlayer film on such a structure or substrate having steps. [Effects of the Invention]

[0049] As described above, the resist underlayer material, pattern formation method, and resist underlayer formation method of the present invention are particularly suitable for use in multilayer resist processes, including planarization of workpieces with steps and irregularities, and are extremely useful in fine patterning for semiconductor device manufacturing. In particular, in fine patterning processes using multilayer resists in semiconductor device manufacturing processes, it is possible to provide a resist underlayer material that has excellent flatness and can be formed independently of the substrate, even on workpieces having particularly difficult-to-planar areas such as wide trench structures, without containing an acid generator, and furthermore, a resist underlayer material with appropriate etching and optical properties, a pattern formation method using the material, and a resist underlayer formation method. In particular, because the base generated by baking, etc., acts on the phenolic hydroxyl group of the crosslinking agent, increasing its ionicity and strengthening its interaction with the substrate surface, it is possible to suppress the occurrence of pinholes and edge shrinkage (decay) even when forming a resist underlayer on a wafer that has undergone hydrophobic treatment such as HMDS treatment. [Brief explanation of the drawing]

[0050] [Figure 1] This is an explanatory diagram illustrating an example of a pattern formation method using the three-layer resist process of the present invention. [Figure 2] This is an explanatory diagram of the edge recession evaluation method in the embodiment. [Figure 3] This is an explanatory diagram of the embedding characteristics evaluation method in the example. [Figure 4] This is an explanatory diagram of the method for evaluating planarization characteristics in the embodiment. [Modes for carrying out the invention]

[0051] As mentioned above, in the fine patterning process using the multilayer resist method in semiconductor device manufacturing processes, there was a need for a resist underlayer material that could form a resist underlayer film with excellent film-forming properties and flatness even on a workpiece substrate having particularly difficult-to-planar areas such as wide trench structures, and further possessing excellent embedding characteristics, appropriate etching characteristics, and optical properties, as well as a pattern formation method using the said material and a resist underlayer film formation method.

[0052] The inventors have been exploring various resist underlayer materials and pattern formation methods to achieve advanced embedding / planarization and excellent film formation properties through underlayer formation in multilayer lithography using resist underlayers. As a result, they have discovered that resist underlayer materials, pattern formation methods using the said materials, and resist underlayer formation methods are extremely effective, as they include compounds that do not contain phenolic hydroxyl groups, or have a residual rate of phenolic hydroxyl groups at the end groups of the compound of less than 2%, and whose polystyrene-equivalent weight-average molecular weight determined by gel permeation chromatography is 2,500 or less, a crosslinking agent containing phenolic hydroxyl groups, and a base generator as the main components. This has led to the completion of the present invention.

[0053] In other words, the present invention is a resist underlayer material comprising (A) a compound that does not contain phenolic hydroxyl groups, or a compound that is modified with phenolic hydroxyl groups and has a residual rate of less than 2% of the phenolic hydroxyl groups, wherein the weight-average molecular weight of the compound in terms of polystyrene, determined by gel permeation chromatography, is 2,500 or less; (B) a crosslinking agent containing phenolic hydroxyl groups represented by the following general formula (1); (C) a base generator; and (D) an organic solvent. [ka] (In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. 16 (where is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; q is an integer from 1 to 5.)

[0054] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0055] <Resist Underlayer Material> The resist underlayer material of the present invention comprises (A) a compound that does not contain phenolic hydroxyl groups, or a compound that is modified with phenolic hydroxyl groups and has a residual rate of phenolic hydroxyl groups of less than 2%, wherein the polystyrene-based weight-average molecular weight of the compound determined by gel permeation chromatography is 2,500 or less; (B) a crosslinking agent containing phenolic hydroxyl groups represented by the following general formula (1); (C) a base generator; and (D) an organic solvent.

[0056] [(A) Compounds for forming a resist underlayer film] The resist underlayer material of the present invention contains (A) a compound that does not contain phenolic hydroxyl groups, or a compound that is modified with phenolic hydroxyl groups with a residual rate of less than 2% of the phenolic hydroxyl groups, and the weight-average molecular weight of the compound in terms of polystyrene, determined by gel permeation chromatography, is 2,500 or less. As a result, it is considered to have good thermal fluidity and therefore possess advanced embedding / planarization characteristics.

[0057] The weight-average molecular weight of component (A) is 2,500 or less, preferably 300 to 2,500, and particularly preferably 500 to 2,000. If the molecular weight is 300 or more, it exhibits excellent film-forming properties and does not contaminate the equipment due to an increase in sublimation during curing. If the molecular weight is 2,500 or less, the complex viscosity of the resin decreases during firing, resulting in high thermal fluidity and excellent planarization / embedding properties. In this invention, the molecular weight can be the weight-average molecular weight (Mw) on a polystyrene basis obtained by gel permeation chromatography (GPC) with tetrahydrofuran as the eluent. The number-average molecular weight (Mn) and dispersion (Mw / Mn) can also be determined in the same way. The dispersion of component (A) can be 1.0 to 2.5, but is more preferably 1.0 to 1.5.

[0058] The aforementioned component (A) includes phenol, o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, 2-phenylphenol, 3-phenylphenol, 4-phenylphenol Phenol, 3,5-diphenylphenol, 2-naphthylphenol, 3-naphthylphenol, 4-naphthylphenol, 4-tritylphenol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, catechol, hydroquinone, 4-tert-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropyl Phenol, 2-methoxy-5-methylphenol, 2-tert-butyl-5-methylphenol, pyrogallol, thymol, isothymol, 4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'dimethyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'diallyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'difluoro-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'diphenyl-4,4'-(9H-fluorene-9 Examples include (-ylidene)bisphenol, 2,2'-dimethoxy-4,4'-(9H-fluorene-9-ylidene)bisphenol, 1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol, 7-methoxy-2-naphthol, and compounds in which the phenolic hydroxyl group contained in dihydroxynaphthalene, hydroxyanthracene, bisphenol, and trisphenol has been chemically modified, such as 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, and 2,6-dihydroxynaphthalene. In addition, low-complex viscosity compounds described in Japanese Patent Application Publication No. 2017-119670 can also be suitably used.

[0059] When synthesizing the above compounds, the reaction to modify the phenolic hydroxyl groups may not proceed completely. If the reaction does not proceed completely, the phenolic hydroxyl groups may remain unsealed. The amount of residual phenolic hydroxyl groups in such component (A) is less than 2%, more preferably less than 1%, and most preferably less than 0.1%, resulting in a compound in which substantially 100% of the phenolic hydroxyl groups are chemically modified and no residual phenolic hydroxyl groups are present. Compounds that do not contain residual phenolic hydroxyl groups tend to have lower complex viscosity in resins compared to compounds containing phenolic hydroxyl groups because there is no contribution from hydrogen bonding of phenolic hydroxyl groups during firing, resulting in higher thermal fluidity and improved planarization / embedding properties. In this invention, the amount of residual phenolic hydroxyl groups can be calculated by 1H NMR.

[0060] Furthermore, it is preferable that the (A) component is represented by the following general formula (8). [ka] (In the formula, W is an n-valent organic group having 2 to 50 carbon atoms. n is an integer from 2 to 10, and Y is independently one of the structures shown in the general formula (9) below.) [ka] (In the formula, the dashed line represents the bond site to W. Z is one or more terminal groups, and at least one of the terminal groups is one of the groups shown in the following general formula (10).) [ka] (In the equation, dashed lines represent connections.)

[0061] In the resist underlayer material of the present invention, the terminal group structure of the general formula (9) functions as a thermosetting group. A particularly preferred structure is when the propargyloxy group is at the beta position of the naphthalene ring, as exemplified by formula (10), and a mechanism of thermosetting via a ring structure as shown in the following reaction equation is presumed. In this case, before curing, it contributes as a substituent that imparts thermal fluidity, but during curing, the curing reaction occurs via a rigid ring structure, making it possible to achieve both thermal fluidity and heat resistance, which are conflicting properties. Since the curing reaction proceeds even without an acid generator, the effect of the base generator can be maximized.

[0062] [ka]

[0063] In the general formula (8) above, W is an n-valent organic group having 2 to 50 carbon atoms, and n is an integer from 2 to 10. Therefore, W is a 2-10 valent organic group with a structure obtained by removing 2 to 10 hydrogen atoms from an organic compound having 2 to 50 carbon atoms. Compounds having an organic group W having 2 to 50 carbon atoms with a structure in which 2 to 10 hydrogen atoms are added to W may contain linear, branched, or cyclic saturated or unsaturated hydrocarbon groups, aromatic groups, heteroaromatic groups, ether groups, hydroxyl groups, ester groups, keto groups, amino groups, halogen groups, sulfide groups, carboxyl groups, sulfo groups, imide groups, cyano groups, aldehyde groups, imino groups, urea groups, carbamate groups, carbonate groups, nitro groups, sulfone groups, etc. For good flatness and sufficient thermosetting properties, n is more preferably 2 to 4.

[0064] In the general formula (9) above, Z is one or more terminal groups, and at least one of the terminal groups is one of the groups represented by the general formula (10). In this case, all Z may be one of the groups represented by the general formula (10).

[0065] Furthermore, in this case, Z in the general formula (9) can be a compound composed of one or more of the groups represented by the general formula (10) and one or more of the groups represented by the following general formulas (11) and (12). [ka] (R in equation (11) above) p R represents a linear, branched, saturated, or unsaturated hydrocarbon group having 1 to 30 carbon atoms, which may be substituted with heteroatoms or may have heteroatoms interposed. q R represents a hydrogen atom or a linear, branched, saturated, or unsaturated hydrocarbon group having 1 to 10 carbon atoms. r The terms represent linear or branched hydrocarbon groups, halogen atoms, nitro groups, amino groups, nitrile groups, alkoxycarbonyl groups, and alkanoyloxy groups with 1 to 10 carbon atoms. m1 represents 0 to 2, m2 and m3 represent the number of substituents on the aromatic ring, m2 and m3 represent integers from 0 to 7, and m2 + m3 satisfies the relationship between 0 and 7. If a is the proportion of the structure of general formula (10) constituting Z, and b is the proportion of the total structure of general formulas (11) and (12), then the relationships a + b = 1.0, 0.50 ≤ a ≤ 0.99, and 0.01 ≤ b ≤ 0.50 are satisfied.

[0066] R in the above general formula (11) p For example, some of the hydrogen atoms of the hydrocarbon group may be replaced by 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 interposed, and as a result, a hydroxyl group, cyano group, carbonyl group, ether bond, ester bond, sulfonic acid ester bond, carbonate bond, lactone ring, sultone ring, carboxylic acid anhydride, haloalkyl group, etc. may be formed or interposed.

[0067] Examples of terminal group structures represented by the general formula (11) above include, but are not limited to, the following. In the following formula, n1 represents an integer from 0 to 29, and n2 represents an integer from 0 to 20.

[0068] [ka] (In the formula, * indicates a bond.)

[0069] [ka] (In the formula, * indicates a bond.)

[0070] Examples of terminal group structures represented by the general formula (12) above include, but are not limited to, the following. In the following formula, n3 represents an integer from 0 to 9.

[0071] [ka] (In the formula, * indicates a bond.)

[0072] Depending on the application, the etching resistance, heat resistance, optical properties, polarity, flexibility, and other properties of the resist underlayer material can be adjusted by appropriately selecting W, Y, and n in the compound of the general formula (8) above. Of these, regarding optical properties, if the resist underlayer material has appropriate optical properties at a wavelength of 193 nm, reflected light during exposure in multilayer ArF lithography can be suppressed, resulting in excellent resolution. In order to suppress reflected light, it is preferable that the optical constants of the resist underlayer material are generally in the range of a refractive index n of 1.4 to 1.9 and an extinction coefficient k of 0.1 to 0.5.

[0073] In the general formula (8) above, W can preferably be exemplified by the structure of the following formula.

[0074] [ka]

[0075] [ka] (In the equation, dashed lines indicate connections.)

[0076] In the present invention, the compound of general formula (8) may be used alone or as a mixture of two or more compounds. It may also be used as a mixture containing the compound represented by general formula (8). When used as a mixture, it is preferable that the compound represented by general formula (8) accounts for 10% by mass or more, and more preferably 20% by mass or more, of the total solid content of the resist underlayer film material excluding the solvent. When it is 10% by mass or more, a sufficient blending effect can be obtained.

[0077] Such compounds for forming resist underlayer films allow for the full benefit of the combined effects of crosslinking agents and base generators, enabling the formation of resist underlayer films with excellent flatness and film-forming properties, and are particularly easy to manufacture.

[0078] [Method for producing compounds] The compound of component (A) used in the resist underlayer material of the present invention can be manufactured by selecting the most optimal method depending on its structure. Below, an example of a method for synthesizing the compound represented by the general formula (8) described above will be detailed. However, the method for manufacturing the compound for forming the resist underlayer of component (A) is not limited to this example.

[0079] For example, it can be obtained by an addition reaction between an epoxy compound and a carboxylic acid compound, as shown in the reaction formulas (1-1) to (1-8) below, or by an addition reaction between an epoxy compound and an alcohol compound, as shown in the reaction formulas (1-9) to (1-12) below.

[0080] [ka] (W, Z, and n are the same as above in the formula.)

[0081] The ratio of the epoxy compound to the carboxylic acid compound or alcohol compound is preferably such that, for every mole of epoxy group in the epoxy compound, there are 0.3 to 2.0 moles, more preferably 0.5 to 1.5 moles, and even more preferably 0.75 to 1.25 moles of carboxyl group in the carboxylic acid compound or hydroxyl group in the alcohol compound. When the amount of carboxyl group or hydroxyl group relative to the amount of epoxy group is appropriate in this way, there is no risk of unreacted epoxy groups remaining and impairing the storage stability of the resist underlayer material, and unreacted carboxylic acid compound or alcohol compound remaining and causing outgassing can be prevented.

[0082] Furthermore, multiple epoxy compounds, carboxylic acid compounds, or alcohol compounds may be used in combination to improve the required performance, such as optical constant (n / k), thermal fluidity, etching resistance, heat resistance, and solvent solubility. In this case as well, it is preferable that the ratio of epoxy groups to carboxylic acid groups or alcohol compounds is within the range described above.

[0083] The compound for forming a resist underlayer film of component (A) in the present invention can usually be obtained by reacting an epoxy compound with a carboxylic acid compound or an alcohol compound in the presence of a reaction catalyst, either in the absence of a solvent or in a solvent, at room temperature or under cooling or heating as necessary.

[0084] Examples of solvents used in this process include alcohols such as methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ethers such as diethyl ether, dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, and isobutyl methyl ketone; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; lactones such as γ-butyrolactone; and aprotic polar solvents such as dimethyl sulfoxide, N,N-dimethylformamide, and hexamethylphosphoric triamide. These can be used individually or in combination of two or more types. These solvents are preferably used in an amount of 0 to 2,000 parts by mass per 100 parts by mass of the reaction raw material.

[0085] Specifically, the reaction catalysts include benzyltriethylammonium chloride, benzyltriethylammonium bromide, benzyltrimethylammonium chloride, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetramethylammonium hydrooxide, tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrabutylammonium hydrogen sulfate, and trioctylmethylammonium Quaternary ammonium salts such as muchloride, tributylbenzylammonium chloride, trimethylbenzylammonium chloride, trimethylbenzylammonium hydrooxide, N-laurylpyridinium chloride, N-lauryl-4-picolinium chloride, N-laurylpicolinium chloride, trimethylphenylammonium bromide, and N-benzylpicolinium chloride; quaternary phosphonium salts such as tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, and tetraphenylphosphonium chloride; tris[2-(2-methoxyethoxy)ethyl]ammonium N, To Examples include tertiary amines such as ris(3,6-dioxaheptyl)amine and tris(3,6-dioxaoctyl)amine. The amount of catalyst used is preferably 0.001 to 100% by mass relative to the raw material, and more preferably in the range of 0.005 to 50% by mass.

[0086] The reaction temperature is preferably between -50°C and the boiling point of the solvent, and more preferably between room temperature and 150°C. The reaction time is appropriately selected from 0.1 to 100 hours.

[0087] The reaction methods include charging the epoxy compound, carboxylic acid compound or alcohol compound, and catalyst all at once; dispersing or dissolving the epoxy compound and carboxylic acid compound or alcohol compound in a solvent, then adding the catalyst all at once or by diluting it with a solvent and adding it dropwise; or dispersing or dissolving the catalyst in a solvent, then adding the epoxy compound and carboxylic acid compound or alcohol compound all at once or by diluting it with a solvent and adding it dropwise. After the reaction is complete, the material may be used as is as a resist underlayer film material, but to remove unreacted raw materials, catalyst, etc. present in the system, it can also be recovered by diluting it with an organic solvent and performing liquid-liquid washing.

[0088] The organic solvent used at this time is not particularly limited as long as it can dissolve the compound and separates into two layers when mixed with water, but examples include hydrocarbons such as hexane, heptane, benzene, toluene, and xylene; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; ketones such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone, and methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, and ethyl cyclopentyl methyl ether; chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene; and mixtures thereof. The washing water used at this time can be what is usually called deionized water or ultrapure water. One or more washes are sufficient, but washing more than 10 times does not necessarily mean that the washing effect will be obtained, so it is preferable to wash about 1 to 5 times.

[0089] During liquid-liquid washing, washing with a basic aqueous solution may be performed to remove unreacted carboxylic acid compounds, alcohol compounds, or acidic components from the system. Specific examples of bases include alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, alkaline earth metal carbonates, ammonia, and organic ammonium compounds.

[0090] Furthermore, in order to remove metal impurities or basic components from the system during liquid-liquid washing, washing with an acidic aqueous solution may be performed. Examples of acids include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and heteropoly acids; and organic acids such as oxalic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid.

[0091] The above-mentioned separation and washing with basic aqueous solutions and acidic aqueous solutions may be performed individually or in combination. From the viewpoint of removing metal impurities, it is preferable to perform the separation and washing in the order of basic aqueous solution followed by acidic aqueous solution.

[0092] After the liquid-liquid washing with the above-mentioned basic and acidic aqueous solutions, further washing with neutral water may be performed. As neutral water, the above-mentioned deionized water or ultrapure water may be used. One or more washes are sufficient, but it is preferable to perform multiple washes to sufficiently remove basic and acidic components. Washing more than 10 times does not necessarily guarantee the same level of effectiveness, so it is preferable to wash 1 to 5 times.

[0093] Furthermore, the reaction product after liquid-liquid washing can be recovered as a powder by concentrating the solvent to dryness or crystallizing it under reduced pressure or atmospheric pressure. However, to improve the handling when preparing the resist underlayer material, it is also possible to keep it in a solution of an appropriate concentration. The concentration at this time is preferably 0.1 to 50% by mass, and more preferably 0.5 to 30% by mass. At such a concentration, the viscosity does not tend to become high, thus preventing impairment of handling, and it is also economical because the amount of solvent does not become excessive.

[0094] The solvent used in this process is not particularly limited as long as it can dissolve the compound, but specific examples include ketones such as cyclohexanone and methyl-2-amyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; and esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate. These can be used individually or in mixtures of two or more types.

[0095] Furthermore, when producing the compound of component (A) in the present invention, epoxy compounds, carboxylic acid compounds, and alcohol compounds can be appropriately combined according to the required performance. More specifically, by synthesizing a compound for forming a resist underlayer film by combining a flexible hydrocarbon structure that contributes to improved embedding / planarization properties and a rigid aromatic ring structure that contributes to etching resistance and heat resistance in any proportion, it is possible to achieve a high level of both embedding / planarization properties and heat resistance / etching resistance.

[0096] As described above, the resist underlayer film forming compound according to the present invention provides a resist underlayer film material that has high embedding / planarization characteristics as well as good heat resistance and dry etching resistance.

[0097] [(B) Crosslinking agent] The resist underlayer material of the present invention, by containing a crosslinking agent containing phenolic hydroxyl groups, enhances curability and further suppresses intermixing with the upper layer. Furthermore, because it contains a crosslinking agent containing phenolic hydroxyl groups, it exhibits excellent substrate affinity, and is therefore considered capable of forming a resist underlayer with excellent film-forming properties even on substrates with complex microstructures and various surface materials. In particular, it exhibits excellent film-forming properties on HMDS-treated hydrophobic substrates.

[0098] In the present invention, the crosslinking agent containing phenolic hydroxyl groups is a polynuclear phenolic crosslinking agent represented by the following general formula (1). When the base generator described below acts on the phenolic hydroxyl groups contained in the polynuclear phenolic crosslinking agent, the interaction with the substrate increases, and a high improvement in film formation performance can be expected. Furthermore, since the crosslinking reaction proceeds even without an acid generator, it is possible to obtain the maximum effect of the base generator. As for the crosslinking agent, the balance of curability, film formation performance, and flatness can be appropriately adjusted by using one type alone or in combination of two or more types. When adding a crosslinking agent, the amount to add is preferably 5 to 60 parts by mass, more preferably 10 to 50 parts by mass, per 100 parts by mass of component (A). If the amount of crosslinking agent added is within the above range, a sufficient improvement in curability and film formation performance can be obtained.

[0099] [ka] (In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. 16 (where is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; q is an integer from 1 to 5.)

[0100] In the general formula (1) above, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. q is an integer from 1 to 5, more preferably 2 or 3. Examples of Q include groups obtained by removing q hydrogen atoms from methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylisopropylbenzene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, and eicosane. 16 The C1-C20 alkyl group is either a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Specific examples of alkyl groups having 1 to 20 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, octyl, ethylhexyl, decyl, and eicosanyl groups, with hydrogen atoms or methyl groups being preferred.

[0101] As examples of compounds represented by the above general formula (1), the following compounds can be specifically cited. Among these, triphenolmethane, triphenolethane, 1,1,1-tris(4-hydroxyphenyl)ethane, and hexamethoxymethylated tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene are preferred from the viewpoint of improving the curability and uniformity of the resist underlayer film.

[0102] [ka]

[0103] [ka] (In the formula, R 16 (This is the same as above.)

[0104] [(C) Base Generator] The resist underlayer material of the present invention, by containing a base generator, can form a resist underlayer with excellent film-forming properties even on a hydrophobic substrate treated with HMDS, for example. To maximize the effect of the base generator, it is preferable not to include an acid generator.

[0105] In the present invention, a base-generating agent is a substance whose chemical structure changes in response to external stimuli such as light or heat, thereby generating a base, and is also called a "latent base" or "base precursor." The base generated may be not only common bases such as ammonia or amines, but also chemical species that have the function of increasing the ionicity of the phenolic hydroxyl group of component (B).

[0106] The base generator of component (C) is not particularly limited, and known base generators can be used as needed. However, when forming a film using the resist underlayer material of the present invention, heating is performed, and it is assumed that the film formation performance is improved when the phenolic hydroxyl group of component (B) becomes ionic during heating, increasing its interaction with the substrate. Therefore, it is preferable that the base generator (C) is a compound that exhibits basicity through thermal decomposition. This is because a resist underlayer material containing such a component (C) allows for a balance between the thermal fluidity of the film and its interaction with the substrate by adjusting the amount of component (C) added.

[0107] When a base generator (also called a thermal base generator) that exhibits basicity through thermal decomposition is used as component (C), the generated base is a cation that has become excessive in the system due to the evaporation or decomposition of anions. Specifically, examples include triphenylsulfonium cations and tetrabutylammonium cations. These increase the ionicity (polarity) of the phenolic hydroxyl group of component (B), and even on substrates that have undergone hydrophobic treatment such as HMDS, they interact with polar groups such as silanol groups present on the surface, improving the wettability of the resist underlayer material to the substrate and suppressing shrinkage of the film edge. On the other hand, before heating, i.e., before base generation, the above effects do not occur, and the fluidity of the resist underlayer material itself is maintained. In this way, a resist underlayer with excellent film-forming properties can be formed.

[0108] Furthermore, it is more preferable that the (C) base generating agent is represented by the following general formulas (2), (3), and (4).

[0109] [ka] (In the above formula, R 01 ~R 03 Each independently represents a linear, branched, or cyclic alkyl or alkenyl group having 1 to 10 carbon atoms, which may be substituted with a heteroatom or may have a heteroatom interposed, or an aryl or aralkyl group having 6 to 18 carbon atoms, which may be substituted with a heteroatom or may have a heteroatom interposed. Also, R 01 , R 02 and R 03 Any two of these may bond with each other to form a ring together with the sulfur atom in the formula. - X represents the organic or inorganic anion that acts as the counterion. - OH - Does not include R. 04 and R 05Each of these is an aryl group having 6 to 20 carbon atoms, which may be independently substituted with a heteroatom or may have a heteroatom interposed therein, and some or all of its hydrogen atoms may be substituted with a linear, branched, or cyclic alkyl or alkoxy group having 1 to 10 carbon atoms. Also, R 04 and R 05 These atoms may bond to each other to form a ring with the iodine atom in the formula. 06 , R 07 , R 08 and R 09 Each independently represents a linear, branched, or cyclic alkyl, alkenyl, or aralkyl group having 1 to 20 carbon atoms, which may be substituted with a hydrogen atom or a heteroatom, or which may have a heteroatom interposed; or an aryl or aralkyl group having 6 to 18 carbon atoms, which may be substituted with a heteroatom, or which may have a heteroatom interposed. Also, R 06 , R 07 , R 08 and R 09 Two or more of these may bond with each other to form a ring with the nitrogen atom in the formula.

[0110] In the above general formula (2), R 01 , R 02 and R 03Specifically, examples include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, and adamantyl group; alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group, hexenyl group, and cyclohexenyl group; aryl groups such as phenyl group, naphthyl group, and thienyl group; and aralkyl groups such as benzyl group, 1-phenylethyl group, and 2-phenylethyl group, with aryl groups being preferred. Furthermore, some of the hydrogen atoms of these groups may be replaced by 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 interposed, resulting in the formation or interposition of hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc.

[0111] R 01 , R 02 and R 03 When any two of these are bonded to each other directly or via an oxygen atom, methylene group, sulfone group, or carbonyl group, examples of substructures other than the dibenzothiophene skeleton and phenoxatiin skeleton shown below can be given, but are not limited to these. In the following formula, substituents may be present at any position on the aromatic ring. [ka]

[0112] More specifically, sulfonium cations include triphenylsulfonium, 4-hydroxyphenyldiphenylsulfonium, bis(4-hydroxyphenyl)phenylsulfonium, tris(4-hydroxyphenyl)sulfonium, 4-tert-butoxyphenyldiphenylsulfonium, bis(4-tert-butoxyphenyl)phenylsulfonium, tris(4-tert-butoxyphenyl)sulfonium, 3-tert-butoxyphenyldiphenylsulfonium, bis(3-tert-butoxyphenyl)phenylsulfonium, tris(3-tert-butoxyphenyl)sulfonium, 4-tert-butylphenyldiphenylsulfonium, tris(4-tert-butylphenyl)sulfonium, 3,4-di-tert-butoxyphenyldiphenylsulfonium, bis(3, Examples include 4-di-tert-butoxyphenyl)phenylsulfonium, tris(3,4-di-tert-butoxyphenyl)sulfonium, diphenyl(4-thiophenoxyphenyl)sulfonium, 10-phenylphenoxatinium, S-phenyldibenzothiophenium, 4-tert-butoxycarbonylmethyloxyphenyldiphenylsulfonium, tris(4-tert-butoxycarbonylmethyloxyphenyl)sulfonium, (4-tert-butoxyphenyl)bis(4-dimethylaminophenyl)sulfonium, tris(4-dimethylaminophenyl)sulfonium, 2-naphthyldiphenylsulfonium, (4-hydroxy-3,5-dimethylphenyl)diphenylsulfonium, and (4-n-hexyloxy-3,5-dimethylphenyl)diphenylsulfonium. Furthermore, examples include 4-methacryloyloxyphenyldiphenylsulfonium, 4-acryloyloxyphenyldiphenylsulfonium, 4-methacryloyloxyphenyldimethylsulfonium, 4-acryloyloxyphenyldimethylsulfonium, (4-methacryloyloxy-3,5-dimethylphenyl)diphenylsulfonium, and (4-acryloyloxy-3,5-dimethylphenyl)diphenylsulfonium.More preferably, examples include triphenylsulfonium, 4-tert-butylphenyldiphenylsulfonium, 4-tert-butoxyphenyldiphenylsulfonium, 10-phenylphenoxatinium, and S-phenyldibenzothiophenium. Among these, triphenylsulfonium, 4-tert-butylphenyldiphenylsulfonium, and 4-tert-butoxyphenyldiphenylsulfonium are preferred.

[0113] R in the general formula (3) 04 and R 05 Specifically, examples include, but are not limited to, phenyl groups, naphthyl groups, tolyl groups, xylyl groups, trimethylphenyl groups, ethylphenyl groups, isopropylphenyl groups, tert-butylphenyl groups, 1-adamantylphenyl groups, triisopropylphenyl groups, tricyclohexylphenyl groups, methoxyphenyl groups, ethoxyphenyl groups, butoxyphenyl groups, hydroxyphenyl groups, dihydroxyphenyl groups, trimethoxyphenyl groups, methylthiophenyl groups, biphenyl groups, fluorophenyl groups, difluorophenyl groups, bromophenyl groups, iodophenyl groups, N,N-diphenylaminophenyl groups, acetoxyphenyl groups, acetylaminophenyl groups, 2,2,2-trifluoroethoxyphenyl groups, (2-methoxyethoxy)phenyl groups, hydroxynaphthyl groups, dihydroxynaphthyl groups, 2,2,2-trifluoroethoxynaphthyl groups, and (2-methoxyethoxy)naphthyl groups, although the substitution position of the substituent is arbitrary.

[0114] R 04 and R 05 Preferably, the phenyl group is an unsubstituted phenyl group, or a phenyl group having a substituent selected from a halogen atom, an alkyl group, or an alkoxy group at the para position of the iodine atom. In particular, phenyl groups, 4-tert-butylphenyl groups, and 4-fluorophenyl groups are preferred.

[0115] R 04 and R 05When these are bonded to each other directly or via an oxygen atom, methylene group, sulfone group, or carbonyl group, the following substructures are examples, but are not limited to them. Note that substituents may be present at any position on the aromatic ring in the following formula. [ka]

[0116] More specifically, the following are examples of iodonium cations, but are not limited to these. In the following formulas, tBu is a tert-butyl group and Ph is a phenyl group.

[0117] [ka]

[0118] Examples of ammonium cations represented by the general formula (4) include ammonia, primary, secondary, and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, and other ammonium cations in which a proton has been added to a nitrogen atom, as well as quaternary ammonium cations.

[0119] Specifically, primary aliphatic ammonium compounds include methylammonium, ethylammonium, n-propylammonium, isopropylammonium, n-butylammonium, isobutylammonium, sec-butylammonium, tert-butylammonium, pentylammonium, tert-amylammonium, cyclopentylammonium, hexylammonium, cyclohexylammonium, heptylammonium, octylammonium, nonylammonium, decylammonium, dodecylammonium, cetylammonium, aminomethylammonium, and 2-aminoethylammonium. Secondary aliphatic ammonium compounds include dimethylammonium, diethylammonium, di-n-propylammonium, diisopropylammonium, di-n-butylammonium, diisobutylammonium, di-sec-butylammonium, dipentylammonium, dicyclopentylammonium, dihexylammonium, dicyclohexylammonium, diheptylammonium, dioctylammonium, dinonylammonium, didecylammonium, didodecylammonium, and dicetylammonium. Examples include methyl(methylamino)methylammonium and methyl-2-(methylamino)ethylammonium, while examples of tertiary aliphatic ammonium compounds include trimethylammonium, triethylammonium, tri-n-propylammonium, triisopropylammonium, tri-n-butylammonium, triisobutylammonium, tri-sec-butylammonium, tripentylammonium, tricyclopentylammonium, trihexylammonium, tricyclohexylammonium, triheptylammonium, trioctylammonium, trinonylammonium, tridecylammonium, tridodecylammonium, tricetylammonium, dimethyl(dimethylamino)methylammonium, and dimethyl(2-dimethylaminoethyl)ammonium.

[0120] Examples of mixed ammonium compounds include dimethylethylammonium, methylpropylammonium, benzylammonium, phenethylammonium, and benzyldimethylammonium. Specific examples of aromatic ammonium compounds and heterocyclic ammonium compounds include anilinium derivatives (e.g., anilinium, N-methylanilinium, N-ethylanilinium, N-propylanilinium, N,N-dimethylanilinium, 2-methylanilinium, 3-methylanilinium, 4-methylanilinium, ethylanilinium at any substitution position, propylanilinium at any substitution position, trimethylanilinium at any substitution position, 2-nitroanilinium, 3-nitroanilinium, 4-nitroanilinium, 2,4-dinitroanilinium, 2,6-dinitroanilinium, 3,5-dinitroanilinium, N,N-dimethyltoluidinium at any substitution position), diphenyl(p-tolyl)ammonium, methyldiphenylammonium, triphenylammonium, aminophenylammonium at any substitution position, naphthylammonium, aminonaphthylammonium at any substitution position, and pyrrolinium derivatives (e.g., pyrrolinium , 2H-pyrrolinium, 1-methylpyrrolinium, 2,4-dimethylpyrrolinium, 2,5-dimethylpyrrolinium, N-methylpyrrolinium, etc.), oxazolium derivatives (e.g., oxazolium, isoxazolium, etc.), thiazolium derivatives (e.g., thiazolium, isothiazolium, etc.), imidazolium derivatives (e.g., imidazolium, 4-methylimidazolium, 4-methyl-2-phenylimidazolium, etc.), pyrazolium derivatives, fluzanium derivatives, pyrrolinium derivatives (e.g., pyrrolinium, 2-methyl-1-pyrrolinium, etc.), pyrrolidinium derivatives (e.g., pyrrolidinium, N-methylpyrrolidinium) (e.g., pyrrolidinonium, N-methylpyrrolidonium), imidazolinium derivatives, imidazolidinium derivatives, pyridinium derivatives (e.g., pyridinium, methylpyridinium, ethylpyridinium, propylpyridinium, butylpyridinium, 4-(1-butylpentyl)pyridinium, dimethylpyridinium, trimethylpyridinium, triethylpyridinium, phenylpyridinium, 3-methyl-2-phenylpyridinium, 4-tert-butylpyridinium, diphenylpyridinium, benzylpyridinium, methoxypyridinium, butoxypyridinium, dimethoxypyridinium, 4-pyrrolidinopyridinium, 2-(1-ethylpropyl)pyridinium, aminopyridinium, dimethyl Examples include minopyridinium, pyridazinium derivatives, pyrimidinium derivatives, pyrazinium derivatives, pyrazolinium derivatives, pyrazolidinium derivatives, piperidinium derivatives, piperadinium derivatives, morpholinium derivatives, indolinium derivatives, isoindolinium derivatives, 1H-indazolinium derivatives, indolinium derivatives, quinolinium derivatives (e.g., quinolinium), isoquinolinium derivatives, sinnolinium derivatives, quinazolinium derivatives, quinoxalinium derivatives, phthalazinium derivatives, priumium derivatives, pteridinium derivatives, carbazolium derivatives, phenanthridineium derivatives, acridinium derivatives, phenadinium derivatives, 1,10-phenanthrolinium derivatives, etc.

[0121] Furthermore, examples of nitrogen-containing compounds having a carboxyl group include carboxyphenylammonium, carboxyindolinium, amino acid derivatives (e.g., protonation products of nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine, methionine, phenylalanine, threonine, lysine, 3-aminopyrazine-2-carboxylic acid, methoxyalanine, etc.), and examples of nitrogen-containing compounds having a sulfonyl group include 3-pyridinium sulfonic acid, and examples of nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, and alcoholic nitrogen-containing compounds include 2-hydroxypyridinium, hydroxyanilinium at any substitution position, hydroxymethylanilinium at any substitution position, hydroxyquinolinium, dihydroxyquinolinium, 2-hydroxyethylammonium, and Examples include s(2-hydroxyethyl)ammonium, tris(2-hydroxyethyl)ammonium, ethylbis(2-hydroxyethyl)ammonium, diethyl(2-hydroxyethyl)ammonium, hydroxypropylammonium, bis(hydroxypropyl)ammonium, tris(hydroxypropyl)ammonium, 4-(2-hydroxyethyl)morpholinium, 2-(2-hydroxyethyl)pyridinium, 1-(2-hydroxyethyl)piperazinium, 1-[2-(2-hydroxyethoxy)ethyl]piperazinium, (2-hydroxyethyl)piperazinium, 1-(2-hydroxyethyl)pyrrolidinium, 1-(2-hydroxyethyl)-2-pyrrolidinonium, 2,3-dihydroxypropylpiperidinium, 2,3-dihydroxypropylpiperidinium, 8-hydroxyeuroridinium, 3-hydroxycuinuclidinium, etc.

[0122] Specific examples of quaternary ammonium salts include tetramethylammonium, triethylmethylammonium, tetraethylammonium, tetrabutylammonium, tetraoctylammonium, didecyldimethylammonium, tridecylmethylammonium, hexadecyltrimethylammonium, stearyltrimethylammonium, benzyltrimethylammonium, benzyltriethylammonium, benzyltributylammonium, and 2-hydroxyethyltrimethylammonium.

[0123] As the ammonium cation, quaternary ammonium cations are preferred, and tetramethylammonium cation, tetraethylammonium cation, and tetrabutylammonium cation are particularly preferred.

[0124] At this time, X in the general formulas (2), (3), and (4) - However, it is more preferable that the structure be represented by any of the following general formulas (5), (6), and (7), or that it be one of the following: chloride ions, bromide ions, iodide ions, fluoride ions, cyanide ions, nitrate ions, or nitrite ions.

[0125] [ka] (In the above formula, R 10 R represents a linear, branched, or cyclic alkyl, alkenyl, aralkyl, or aryl group having 1 to 20 carbon atoms, which may include an ether group, ester group, or carbonyl group, and the hydrogen atoms of these groups may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. 11 R represents an aryl group having 1 to 20 carbon atoms. The hydrogen atoms of the aryl group may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. 12 , R 13 , R 14Each of these independently represents a hydrogen atom, a halogen atom other than a fluorine atom, or a linear, branched, or cyclic alkyl, alkenyl, aralkyl, or aryl group having 1 to 20 carbon atoms, which may also contain an ether group, an ester group, or a carbonyl group, and the hydrogen atoms of these groups may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. 12 , R 13 , R 14 Two or more of these may be bonded together to form a ring.

[0126] Specific examples of carboxylic acid anions represented by the general formula (5) above include formate anion, acetate anion, propionate anion, butyrate anion, isobutyrate anion, valerate anion, isovalerate anion, pivalate anion, hexanoate anion, octanoate anion, cyclohexanecarboxylic acid anion, cyclohexyl acetate anion, laurate anion, myristate anion, palmitate anion, stearate anion, phenyl acetate anion, diphenyl acetate anion, phenoxyacetate anion, mandelate anion, benzoylformate anion, cinnamate anion, dihydrocinnamate anion, benzoate anion, methylbenzoate anion, salicylate anion, naphthalenecarboxylic acid anion, anthracenecarboxylic acid anion, anthraquinonecarboxylic acid anion, hydroxyacetate anion, pivalate anion, lactate anion, methoxyacetate anion, 2-(2 Examples include the -methoxyethoxy)acetate anion, 2-(2-(2-methoxyethoxy)ethoxy)acetate anion, diphenolic acid anion, monochloroacetate anion, dichloroacetate anion, trichloroacetate anion, trifluoroacetate anion, pentafluoropropionate anion, heptafluorobutyrate anion, and 2-hydroxy-2,2-bis(trifluoromethyl)acetate anion. Other examples include monoanions of dicarboxylic acids such as succinic acid, tartaric acid, glutaric acid, pimelic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, and cyclohexenedicarboxylic acid.

[0127] Specific examples of the arene sulfonate anion represented by the general formula (6) above include benzenesulfonate, 4-toluenesulfonate, 2-toluenesulfonate, xylenesulfonate at any substitution position, trimethylbenzenesulfonate, mesitylenesulfonate, 4-methoxybenzenesulfonate, 4-ethylbenzenesulfonate, 2,4,6-triisopropylbenzenesulfonate, 1-naphthalenesulfonate, 2-naphthalenesulfonate, anthraquinone-1-sulfonate, anthraquinone-2-sulfonate, 4-(4-methylbenzenesulfonyloxy)benzenesulfonate, 3,4-bis(4-methylbenzenesulfonyloxy)benzenesulfonate, 6-(4-methylbenzenesulfonyloxy)naphthalene-2-sulfonate, 4-phenyloxybenzenesulfonate, 4-diphenylmethylbenzenesulfonate, 2,4-dinitrobenzenesulfonate, and dodecylbenzenesulfonate.

[0128] Specific examples of the alkanesulfonate anion represented by the general formula (7) above include methanesulfonate, ethanesulfonate, propanesulfonate, butanesulfonate, pentanesulfonate, hexanesulfonate, cyclohexanesulfonate, octanesulfonate, and 10-camphorsulfonate.

[0129] Furthermore, X in the general formulas (2), (3), and (4) - It is more preferable that the boiling point of the conjugate acid XH is 200°C or lower. In this specification, the boiling point is the value at 1 atmosphere (1013 hPa).

[0130] X in the above general formulas (2), (3), and (4) - Particularly preferred are trifluoroacetate anion, pentafluoropropionate anion, 2-hydroxy-2,2-bis(trifluoromethyl)acetate anion, chloride ion, and nitrate ion.

[0131] The (C) base generator can be any combination of the specific cations and anions mentioned above, but is not limited to these. Furthermore, the following is a preferred structure. In the following formula, tBu represents a tert-butyl group.

[0132] [ka]

[0133] The (C) base generator can be used alone or in combination of two or more types to exhibit basicity in accordance with the firing temperature of the resist underlayer material, and the balance between film formation and flatness on hydrophobic substrates can be appropriately adjusted. When adding the base generator, the amount to be added is preferably 0.5 to 20 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the (B) crosslinking agent. If the amount of base generator added is within the above range, a sufficient film formation improvement effect can be obtained, and there is no risk of problems such as deterioration of in-plane uniformity of the film due to decomposition and sublimation, or a decrease in the curability of the compound or resin due to basicity.

[0134] [(D) Organic solvents] The (D) organic solvent that can be used in the resist underlayer film material of the present invention is not particularly limited as long as it can dissolve (A) one or more compounds, (B) one or more crosslinking agents, and (C) base generators, and is preferably one that can dissolve (E) surfactants, (F) plasticizers, and (G) dyes, which will be described later.

[0135] Specifically, solvents described in paragraphs

[0091] to

[0092] of Japanese Patent Publication No. 2007-199653 can be added. More specifically, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, 2-heptanone, cyclopentanone, cyclohexanone, diacetone alcohol, ethyl lactate, and γ-butyrolactone, or a mixture containing one or more of these, are preferably used.

[0136] The amount of organic solvent added should preferably be adjusted according to the desired film thickness of the resist underlayer, but it is usually in the range of 100 to 50,000 parts by mass per 100 parts by mass of the (A) compound (component (A)).

[0137] Furthermore, in the resist underlayer material of the present invention, it is preferable that (D) the organic solvent is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher (hereinafter also referred to as "high-boiling point solvents").

[0138] Examples of organic solvents with a boiling point below 180°C include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, 2-heptanone, cyclopentanone, and cyclohexanone.

[0139] As for organic solvents with a boiling point of 180°C or higher, there are no particular restrictions on hydrocarbons, alcohols, ketones, esters, ethers, chlorinated solvents, etc., as long as they can dissolve each component of the resist underlayer film material of the present invention. Specific examples include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-Hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, n-nonyl acetate, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, diethylene glycol diacetate, diethylene glycol dibenzoate, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol-n-butyl ether, triethylene glycol Recall butyl methyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, triethylene glycol diacetate, triethylene glycol dibenzoate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetin, propylene glycol diacetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, 1,Examples include 6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, benzyl benzoate, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, and dibutyl adipate, which may be used individually or in combination.

[0140] The organic solvent with a boiling point of 180°C or higher can be appropriately selected from the above-mentioned options, for example, according to the temperature at which the resist underlayer material of the present invention is heat-treated. The boiling point of the organic solvent with a boiling point of 180°C or higher is preferably 180°C to 300°C, and more preferably 200°C to 300°C. With such a boiling point, there is no risk of excessive volatilization during baking (heat treatment) due to a boiling point that is too low, so sufficient thermal fluidity can be obtained during film formation, and it is thought that a resist underlayer film with excellent embedding / planarization properties can be formed. Furthermore, with such a boiling point, there is no risk of the solvent remaining in the film without volatilizing after baking due to a boiling point that is too high, so there is no risk of adverse effects on film properties such as etching resistance.

[0141] Furthermore, when using an organic solvent with a boiling point of 180°C or higher, the amount blended is preferably 1 to 30 parts by mass per 100 parts by mass of the organic solvent with a boiling point of less than 180°C. This blending amount is preferable because it avoids the risk of the blending amount being too low to provide sufficient thermal fluidity during baking, or the blending amount being too high, which could remain in the film and lead to deterioration of film properties such as etching resistance.

[0142] [(E) Surfactants] The resist underlayer material of the present invention may contain (E) a surfactant to improve the coatability in spin coating. As the surfactant, for example, those described in

[0142] to

[0147] of Japanese Patent Application Publication No. 2009-269953 can be used. When adding a surfactant, the amount to be added is preferably 0.001 to 20 parts by mass, more preferably 0.01 to 10 parts by mass, per 100 parts by mass of component (A).

[0143] [(F) Plasticizer] Furthermore, to further improve the planarization / embedding properties, a plasticizer (F) may be added to the resist underlayer material of the present invention. The plasticizer is not particularly limited, and various known types of plasticizers can be widely used. Examples include low molecular weight compounds such as phthalates, adipicates, phosphates, trimelliticates, and citrates, as well as polymers such as polyethers, polyesters, and polyacetal polymers described in Japanese Patent Application Publication No. 2013-253227. When adding a plasticizer, the amount added is preferably 5 to 500 parts by mass, more preferably 10 to 200 parts by mass, per 100 parts by mass of component (A).

[0144] [(G)Dye] Furthermore, the resist underlayer material of the present invention may be enriched with (G) dyes to further improve the resolution during patterning in multilayer lithography. The dye is not particularly limited as long as it is a compound that has appropriate absorption at the exposure wavelength, and a wide variety of known compounds can be used. Examples include benzenes, naphthalenes, anthracenes, phenanthrenes, pyrenes, isocyanuric acids, and triazines. When adding a dye, the amount added is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of component (A).

[0145] <Pattern Formation Method> Furthermore, the present invention provides a method for forming a pattern on a substrate to be processed, (I-1) A step of forming a resist underlayer film by applying the above resist underlayer film material onto a substrate to be processed and then heat-treating it. (I-2) A step of forming a resist upper layer on the resist lower layer using a photoresist material, (I-3) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (I-4) A step of transferring the pattern to the resist underlayer by dry etching using the resist upper layer on which the above pattern is formed as a mask, and (I-5) A step of processing the substrate to be processed using the resist underlayer film on which the above pattern has been formed as a mask to form a pattern on the substrate to be processed. A pattern formation method having [a specific characteristic] is provided (a two-layer resist process).

[0146] Furthermore, a method for forming a pattern on a substrate to be processed, (II-1) A step of forming a resist underlayer film by applying the above resist underlayer film material onto a substrate to be processed and then heat-treating it. (II-2) A step of forming a resist interlayer on the resist underlayer, (II-3) A step of forming a resist upper layer film on the resist interlayer film using a photoresist material, (II-4) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (II-5) Using the resist upper layer film on which the above pattern is formed as a mask, a step of transferring the pattern to the resist interlayer film by dry etching. (II-6) A step of transferring the pattern to the resist underlayer film by dry etching using the resist interlayer film on which the above pattern has been transferred as a mask, and (II-7) A step of processing the substrate to be processed using the resist underlayer film on which the above pattern has been formed as a mask to form a pattern on the substrate to be processed. A pattern formation method having the following characteristics is provided (3-layer resist process).

[0147] In addition, a method for forming a pattern on a substrate to be processed, (III-1) A step of forming a resist underlayer film by applying the above resist underlayer film material onto a substrate to be processed and then heat-treating it. (III-2) A step of forming an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the resist underlayer film described above. (III-3) A step of forming an organic thin film on the inorganic hard mask interlayer described above. (III-4) A step of forming a resist upper layer film on the above organic thin film using a photoresist material, (III-5) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (III-6) A step of transferring the pattern to the organic thin film and the inorganic hard mask interlayer film by dry etching, using the resist upper layer film on which the above pattern is formed as a mask. (III-7) A step of transferring the pattern to the resist underlayer film by dry etching using the inorganic hard mask interlayer film on which the above pattern has been transferred as a mask, and (III-8) A step of processing the substrate to be processed using the resist underlayer film on which the above pattern has been formed as a mask to form a pattern on the substrate to be processed. A pattern formation method having the following characteristics is provided (4-layer resist process).

[0148] The thickness of the resist underlayer used in the present invention is selected as appropriate, but is preferably 2 to 20,000 nm, and particularly preferably 50 to 15,000 nm. In the case of a resist underlayer for a 3-layer process, a silicon-containing resist interlayer (interlayer film) or a silicon-free resist upper layer can be formed on it. In the case of a resist underlayer for a 2-layer process, a silicon-containing resist upper layer or a silicon-free resist upper layer can be formed on it.

[0149] The pattern formation method of the present invention is suitably used in multilayer resist processes such as a silicon-containing two-layer resist process, a silicon-containing three-layer resist process using a silicon-containing interlayer, a silicon-containing four-layer resist process using a silicon-containing interlayer and an organic thin film, and a silicon-free two-layer resist process.

[0150] [3-layer resist process] The pattern formation method of the present invention will be described below using a three-layer resist process as an example, but is not limited to this process. In this case, a resist underlayer film is formed on a substrate using the above-mentioned resist underlayer film material, a resist interlayer film is formed on the resist underlayer film using a resist interlayer film material containing silicon atoms, a resist upper layer film is formed on the resist interlayer film using a resist upper layer film material of a photoresist composition to form a multilayer resist film, a pattern circuit region of the resist upper layer film is exposed, and then developed with a developer to form a resist pattern on the resist upper layer film, the resist interlayer film with the pattern formed on it is used as a mask to etch the resist underlayer film, and further, the substrate can be processed using the resist underlayer film with the pattern formed on it as a mask to form a pattern on the substrate.

[0151] Since the resist interlayer containing silicon atoms exhibits etching resistance to oxygen gas or hydrogen gas, it is preferable to perform the etching of the resist underlying film using the resist interlayer as a mask, as described above, using an etching gas mainly composed of oxygen gas or hydrogen gas.

[0152] Furthermore, in the pattern formation method of the present invention, at least a resist underlayer film is formed on a substrate using the resist underlayer film material, an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the resist underlayer film, a resist upper layer film is formed on the inorganic hard mask interlayer film using a resist upper layer film material made of a photoresist composition, the pattern circuit region of the resist upper layer film is exposed, and then developed with a developer to form a resist pattern on the resist upper layer film, the obtained resist pattern is used as an etching mask to etch the inorganic hard mask interlayer film, the obtained inorganic hard mask interlayer film pattern is used as an etching mask to etch the resist underlayer film, and the obtained resist underlayer film pattern is used as a mask to process the substrate and form a pattern on the substrate.

[0153] As described above, when forming an inorganic hard mask interlayer on a resist underlayer, silicon oxide films, silicon nitride films, and silicon oxynitride films (SiON films) are formed by methods such as CVD or ALD. Methods for forming nitride films are described in Japanese Patent Application Publication No. 2002-334869 and WO2004 / 066377. The thickness of the inorganic hard mask is 5 to 200 nm, preferably 10 to 100 nm, and among these, the SiON film, which has a high effect as an anti-reflective film, is most preferably used for ArF exposure applications.

[0154] For the silicon-containing resist interlayer in a three-layer resist process, a polysilsesquioxane-based interlayer can be suitably used. A polysilsesquioxane-based interlayer can easily provide an anti-reflective effect in excimer exposure, thereby suppressing reflected light during pattern exposure of the resist upper layer and offering the advantage of excellent resolution. In particular, for 193nm exposure, using a material containing many aromatic groups as the resist lower layer increases the k value and increases substrate reflectivity, but by suppressing reflection with the resist interlayer, substrate reflectivity can be reduced to 0.5% or less. As a resist interlayer with an anti-reflective effect, anthracene is preferably used for 248nm and 157nm exposure, and polysilsesquioxane, which has phenyl groups or absorbent groups having silicon-silicon bonds pendanted to it and is crosslinked with acid or heat, is preferably used for 193nm exposure.

[0155] In this case, forming a silicon-containing resist interlayer by spin coating is simpler and more cost-effective than using CVD.

[0156] The top resist layer in a three-layer resist film can be either positive or negative, and the same photoresist composition as commonly used can be used. When forming the top resist layer with the above photoresist composition, a spin coating method is preferably used, similar to when forming the bottom resist layer. After spin coating the photoresist composition, pre-baking is performed, preferably at 60 to 180°C for 10 to 300 seconds. Thereafter, exposure is performed according to a conventional method, followed by post-exposure baking (PEB) and development to obtain the resist pattern. The thickness of the top resist layer is not particularly limited, but 30 to 500 nm, and particularly 50 to 400 nm, is preferred.

[0157] Furthermore, examples of exposure light include high-energy rays with wavelengths of 300 nm or less, specifically excimer lasers with wavelengths of 248 nm, 193 nm, and 157 nm, soft X-rays of 3 to 20 nm, electron beams, and X-rays with wavelengths of less than 3 nm.

[0158] Next, etching is performed using the obtained resist pattern as a mask. In the three-layer process, etching of the resist interlayer is performed using a fluorocarbon gas with the resist pattern as a mask. Then, etching of the resist underlayer is performed using oxygen gas or hydrogen gas with the resist interlayer pattern as a mask.

[0159] The etching of the next substrate to be processed can also be performed by conventional methods. For example, if the substrate is SiO2, SiN, or a silica-based low dielectric constant insulating film, etching is performed mainly with a fluorocarbon gas. If it is p-Si, Al, or W, etching is performed mainly with a chlorine-based or bromine-based gas. When the substrate is etched with a fluorocarbon gas, the silicon-containing interlayer in the 3-layer process is peeled off simultaneously with the substrate processing. When the substrate is etched with a chlorine-based or bromine-based gas, the silicon-containing interlayer needs to be peeled off separately after the substrate processing, such as by dry etching with a fluorocarbon gas.

[0160] The substrate to be processed is one on which the processing layer is formed. The substrate is not particularly limited and can be made of a different material from the processing layer, such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, Al, etc. The processing layer can be made of various low-k films and their stopper films, such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, TiN, W-Si, Al, Cu, Al-Si, etc., and is usually formed to a thickness of 50 to 10,000 nm, and especially 100 to 5,000 nm. Furthermore, a substrate with a static contact angle with water of 50° or more can be preferably used as the substrate to be processed.

[0161] The pattern formation method of the present invention is also suitable for processing structures with a height of 30 nm or more, or stepped substrates having steps. By depositing the resist underlayer material of the present invention onto a stepped substrate and performing embedding and planarization, it becomes possible to make the thickness of the subsequently deposited resist interlayer and resist upper layers uniform, which facilitates securing the depth of field (DOF) during photolithography and is highly preferable. Furthermore, it is also useful when using a substrate with a static contact angle to water of 50° or more as the substrate to be processed.

[0162] An example of a three-layer resist process is shown below using Figure 1. In the three-layer resist process, as shown in Figure 1(A), a resist underlayer 3 is formed on the workpiece layer 2 stacked on the substrate 1, then a resist interlayer 4 is formed, and finally a resist upper layer 5 is formed on top of that.

[0163] Next, as shown in Figure 1(B), the required portion 6 of the resist upper layer film is exposed, and PEB (post-exposure bake) and development are performed to form the resist upper layer film pattern 5a (Figure 1(C)). Using this obtained resist upper layer film pattern 5a as a mask, the resist interlayer film 4 is etched using a CF-based gas to form the resist interlayer film pattern 4a (Figure 1(D)). After removing the resist upper layer film pattern 5a, the resist lower layer film 3 is etched using an oxygen-based or hydrogen-based plasma etching method with this obtained resist interlayer film pattern 4a as a mask to form the resist lower layer film pattern 3a (Figure 1(E)). Furthermore, after removing the resist interlayer film pattern 4a, the layer to be processed 2 is etched using the resist lower layer film pattern 3a as a mask to form pattern 2a (Figure 1(F)).

[0164] When using an inorganic hard mask interlayer, the resist interlayer 4 is the inorganic hard mask interlayer. When laying an organic thin film, an organic thin film layer is provided between the resist interlayer 4 and the resist upper layer 5. Etching of the organic thin film may be performed consecutively prior to etching of the resist interlayer 4, or the etching of the organic thin film alone may be performed first, and then the etching of the resist interlayer 4 may be performed by changing the etching equipment.

[0165] [4-layer resist process] Furthermore, the present invention can also be suitably used in a four-layer resist process using an organic thin film. In this case, at least a resist underlayer film is formed on a substrate using the resist underlayer film material, an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the resist underlayer film, an organic thin film is formed on the inorganic hard mask interlayer film, a resist upper layer film is formed on the organic thin film using a resist upper layer film material made of a photoresist composition, a pattern circuit region of the resist upper layer film is exposed, and then developed with a developer to form a resist pattern on the resist upper layer film, the obtained resist pattern is used as an etching mask to etch the organic thin film and the inorganic hard mask interlayer film, the obtained inorganic hard mask interlayer film pattern is used as an etching mask to etch the resist underlayer film, and the obtained resist underlayer film pattern is used as a mask to process the substrate and form a pattern on the substrate.

[0166] While a photoresist film may be formed as a resist top layer on top of a resist interlayer, as described above, an organic thin film may be formed on top of the resist interlayer by spin coating, and then a photoresist film may be formed on top of that. When a SiON film is used as the resist interlayer and an organic anti-reflective film (BARC) having absorbent groups at the exposure wavelength is used as the organic thin film, reflection can be suppressed even in immersion lithography with high NA values ​​exceeding 1.0 in excimer lithography by the two layers of anti-reflective films consisting of the SiON film and the organic thin film. Another advantage of forming an organic thin film is that it reduces the trailing of the photoresist pattern directly on top of the SiON. Furthermore, when an adhesion film (ADL) with excellent affinity to the top layer photoresist is used as the organic thin film, it is also advantageous that the pattern collapse of the photoresist can be suppressed.

[0167] <Method for forming a resist underlayer film> The present invention provides a method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of semiconductor devices, comprising: rotating and coating the above-mentioned resist underlayer film material onto a substrate to be processed; and heat-treating the substrate coated with the resist underlayer film material at a temperature of 100°C to 600°C for a range of 10 to 600 seconds to cure and form a resist underlayer film (cured film).

[0168] Furthermore, the present invention provides a method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of semiconductor devices, wherein the resist underlayer film material is applied by rotation onto a substrate to be processed, and the substrate coated with the resist underlayer film material is heat-treated in an atmosphere with an oxygen concentration of 1% by volume or more and 21% by volume or less to cure and form a resist underlayer film (cured film).

[0169] Alternatively, the present invention provides a method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of semiconductor devices, wherein the resist underlayer film material is applied by rotation onto a substrate to be processed, and the substrate coated with the resist underlayer film material is heat-treated in an atmosphere with an oxygen concentration of less than 1 volume% to cure and form a resist underlayer film (cured film).

[0170] In the resist underlayer film formation method of the present invention, the above-mentioned resist underlayer film material is coated onto a substrate to be processed using a spin coating method or the like. By using a spin coating method or the like, good embedding characteristics can be obtained. After spin coating, the solvent is evaporated and baking is performed to promote the crosslinking reaction in order to prevent mixing with the resist upper layer film or resist interlayer film. Baking is performed in a temperature range of 100°C to 600°C, preferably 100°C to 300°C, more preferably 150°C to 280°C, for a period of 10 seconds to 600 seconds, preferably 10 to 300 seconds. By appropriately adjusting the baking temperature and time within the above range, planarization / embedding characteristics and curing characteristics suitable for the application can be obtained. At a baking temperature of 100°C or higher, curing proceeds sufficiently and mixing with the upper layer film or interlayer film does not occur. If the baking temperature is 600°C or lower, thermal decomposition of the base resin can be suppressed, the film thickness does not decrease, and the film surface becomes uniform.

[0171] During baking, either an oxygen-containing atmosphere such as air (oxygen concentration of 1% to 21% by volume) or a non-oxygen atmosphere such as nitrogen can be selected as needed. For example, if the substrate to be processed is susceptible to air oxidation, damage to the substrate can be suppressed by heat treatment in an atmosphere with an oxygen concentration of less than 1% by volume (non-oxygen atmosphere) to form a hardened film.

[0172] Furthermore, the resist underlayer film formation method of the present invention also preferably uses a substrate having a structure or step with a height of 30 nm or more as the substrate to be processed. The resist underlayer film formation method of the present invention is particularly useful when forming a void-free planar organic film on a substrate having a structure or step with a height of 30 nm or more. Moreover, it is also useful when using a substrate with a static contact angle with water of 50° or more as the substrate to be processed. [Examples]

[0173] Hereinafter, the present invention will be specifically described by showing examples and comparative examples, but the present invention is not limited by these descriptions. The measurement of molecular weight and dispersity was carried out by the following methods. The weight average molecular weight (Mw) in terms of polystyrene and the dispersity (Mw / Mn) were determined by gel permeation chromatography (GPC) using tetrahydrofuran as an eluent. In addition, the introduction ratio of the end group and the residual ratio of the phenolic hydroxyl group of the end group were calculated by 1H NMR.

[0174] Synthesis Example: Synthesis of Compounds for Resist Underlayer Materials For the synthesis of the compounds (D1) to (D19) for the resist underlayer film material and the compounds (R1) to (R3) for the comparative examples, the following carboxylic acid group-containing compounds: compound group A (A1) to (A14), hydroxyl group-containing compound (B1), and epoxy group-containing compounds: compound group C (C1) to (C12) were used.

[0175] Compound group A:

Chemical formula

[0176] Compound (B1):

Chemical formula

[0177] Compound group C:

Chemical formula

[0178] [Synthesis Example 1] Synthesis of Compound (D1) [ka] 14.6 g of carboxylic acid compound (A1), 14.0 g of epoxy compound (C1), and 60 g of 2-methoxy-1-propanol were stirred under a nitrogen atmosphere at an internal temperature of 100°C to obtain a homogeneous solution. Then, 1.00 g of benzyltriethylammonium chloride was added and the mixture was stirred at an internal temperature of 110°C for 12 hours. After cooling to room temperature, 200 ml of methyl isobutyl ketone was added, and the mixture was washed twice with 100 g of 1 wt% aqueous ammonia solution, twice with 100 g of 3% aqueous nitric acid solution, and five times with 100 g of ultrapure water. The organic layer was dried under reduced pressure to obtain compound (D1). Using GPC, the weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined to be Mw = 880 and Mw / Mn = 1.03, respectively.

[0179] [Synthesis Examples 2-17] Synthesis of Compounds (D2)-(D17) Except for using compound group A, compound (B1), and compound group C shown in Table 1, compounds (D2) to (D17), as shown in Tables 2 to 4, were obtained as products under the same conditions as in Synthesis Example 1. The weight-average molecular weight (Mw), dispersion (Mw / Mn), and, in cases where two or more carboxylic acid compounds were used, terminal group ratios were determined and are shown in Tables 2 to 4.

[0180] [Table 1]

[0181] [Table 2]

[0182] [Table 3]

[0183] [Table 4]

[0184] [Synthesis Example 18] Synthesis of Compound (D18) [Chemical Formula] 15.9 g of Compound (D5), 4.0 g of acryloyl chloride, and 50 g of N-methylpyrrolidone were added and stirred, and 4.5 g of triethylamine was added dropwise thereto, followed by stirring for 24 hours. Ethyl acetate was added for dilution, and after washing with water three times, silica gel chromatography was performed purification to obtain Compound (D18). When the weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, Mw = 1200 and Mw / Mn = 1.05.

[0185] [Synthesis Example 19] Synthesis of Compound (D19) [Chemical Formula] Compound (D19) was obtained as a product under the same conditions as in Synthesis Example 18, except that Compound (D10) was used. When the weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, Mw = 1640 and Mw / Mn = 1.27.

[0186] [Synthesis Examples 20 to 22] Synthesis of Comparative Compounds (R1) to (R3) [Chemical Formula] 18.8 g of carboxylic acid compound (A14), 20.5 g of epoxy compound (C5), and 60 g of 2-methoxy-1-propanol were stirred under a nitrogen atmosphere at an internal temperature of 100°C to form a homogeneous solution. Then, 1.00 g of benzyltriethylammonium chloride was added and the mixture was stirred at an internal temperature of 110°C for 12 hours. After cooling to room temperature, 200 ml of methyl isobutyl ketone was added, and the mixture was washed twice with 100 g of 1 wt% aqueous ammonia solution and three times with 100 g of ultrapure water. The mixture was then concentrated under reduced pressure to synthesize an intermediate. 60 g of dimethylformamide and 15.9 g of potassium carbonate were added to the obtained intermediate and stirred. Propargylbromide (80% toluene solution) in the amounts shown in Table 5 was added dropwise, and the mixture was stirred under a nitrogen atmosphere at an internal temperature of 50°C for 20 hours. After cooling to room temperature, 200 ml of methyl isobutyl ketone was added, and the mixture was washed twice with 100 g of 3% aqueous nitric acid solution and five times with 100 g of ultrapure water. The organic layers were dried under reduced pressure to obtain compounds (R1) to (R3). The weight-average molecular weight (Mw), dispersion (Mw / Mn) determined by GPC, and the remaining percentage of phenolic hydroxyl groups at the terminal groups determined by 1H NMR are shown in Table 5.

[0187] [Table 5]

[0188] [Synthesis Example 23] Synthesis of Comparative Polymer (R4) [ka] 78.8 g of 2,7-dipropargyloxynaphthalene, 21.6 g of 37% formalin solution, and 250 g of 1,2-dichloroethane were mixed under a nitrogen atmosphere at a liquid temperature of 70°C to form a homogeneous solution. Then, 5 g of methanesulfonic acid was slowly added, and the mixture was stirred at a liquid temperature of 80°C for 12 hours. After cooling to room temperature, 500 g of methyl isobutyl ketone was added, and the organic layer was washed five times with 200 g of pure water. The organic layer was then dried under reduced pressure. 300 mL of THF was added to the residue, and the polymer was reprecipitated with 2000 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain comparative polymer (R4). Using GPC, the weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined to be Mw = 2700 and Mw / Mn = 1.54.

[0189] [Synthesis Example 24] Synthesis of Comparative Polymer (R5) [ka] 54.1 g of m-cresol, 32.5 g of 37% formalin solution, and 250 g of 2-methoxy-1-propanol were mixed under a nitrogen atmosphere at a temperature of 80°C to form a homogeneous solution. Then, 18 g of 20% p-toluenesulfonic acid 2-methoxy-1-propanol solution was slowly added, and the mixture was stirred at a temperature of 110°C for 12 hours. After cooling to room temperature, 500 g of methyl isobutyl ketone was added, and the organic layer was washed five times with 200 g of pure water. The organic layer was then dried under reduced pressure. 300 mL of THF was added to the residue, and the polymer was reprecipitation with 2,000 mL of hexane. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain comparative polymer (R5). Using GPC, the average polymerization molecular weight (Mw) and dispersion (Mw / Mn) were determined to be Mw = 6,900 and Mw / Mn = 5.53.

[0190] Preparation of resist underlayer materials (UDL-1 to 23, comparative UDL-1 to 9) The above compounds and polymers (D1) to (D19), (R1) to (R5), (X1) to (X5) as crosslinking agents, (BG1) to (BG3) as base generators, (AG1) as an acid generator, and propylene glycol monomethyl ether acetate (PGMEA) containing 0.1% by mass of tripropylene glycol monomethyl ether (TPM): boiling point 242°C, 1,6-diacetoxyhexane (1,6-DAH): boiling point 260°C, and PF6320 (manufactured by OMNOVA) were dissolved in the proportions shown in Table 6, and then filtered through a 0.1 μm fluororesin filter to prepare resist underlayer film materials (UDL-1 to 23, comparative UDL-1 to 9).

[0191] [ka]

[0192] [ka]

[0193] [ka]

[0194] [Table 6]

[0195] Example 1: Evaluation of film formation properties (Examples 1-1 to 1-23, Comparative Examples 1-1 to 1-9) The resist underlayer materials prepared above (UDL-1 to 23, comparative UDL-1 to 9) were applied to bare-Si substrates, SiON-treated substrates, and hexamethyldisilazane (HMDS)-treated substrates shown in Table 7. The materials were then fired at 250°C for 60 seconds to form a resist underlayer with a thickness of 100 nm. The formed organic films were then observed using an optical microscope (Nikon ECLIPSE L200) to check for any coating abnormalities. The water contact angles of each substrate were measured using a contact angle meter (Kyowa Interface Science DM-701R). The results showed that the bare-Si substrate had a contact angle of less than 15°, the SiON-treated substrate had a contact angle of 46°, and the HMDS-treated (90°C × 60 seconds) substrate had a contact angle of 58°. A higher contact angle indicates a more hydrophobic substrate surface, making film formation more difficult. Furthermore, in this evaluation, the film thickness was kept thin to assess the quality of coating, resulting in strict evaluation conditions where film formation abnormalities are likely to occur.

[0196] [Table 7]

[0197] As shown in Table 7, the resist underlayer material of the present invention was able to form a uniform resist underlayer film without coating abnormalities on SiON-treated substrates and HMDS-treated (90°C × 60 seconds) substrates. Comparing the results of Examples 1-1 to 1-23 and Comparative Examples 1-1 to 1-3, it can be confirmed that the film formation performance is improved by the combination of a crosslinking agent containing phenolic hydroxyl groups and a base generator, indicating the usefulness of the present invention. In Comparative Example 1-9, however, the resist underlayer material did not contain phenolic hydroxyl groups, and a thermal acid generator was required for curing, so the film formation improvement effect of the base generator was not obtained. On the other hand, in Comparative Examples 1-4 to 1-6, which contain phenolic hydroxyl group-containing compounds, and Comparative Examples 1-7 and 1-8, which contain polymers, film formation was possible regardless of the type of substrate.

[0198] Example 2: Evaluation of edge tide recession (Examples 2-1 to 2-23, Comparative Examples 2-1 to 2-9) The resist underlayer materials prepared above (UDL-1 to 23, comparative UDL-1 to 9) were coated onto 12-inch bare-Si substrates and HMDS-treated (90°C x 60 seconds) substrates with an edge cut width of 2 mm, respectively, and baked at 250°C for 60 seconds to form a resist underlayer with a thickness of 100 nm (7 in Figure 2(G)). The formed resist underlayer was measured using a film thickness measuring device (Atlas-XP, manufactured by Onto Innovation). + Using a 3D printer, measurements were taken at four locations on each substrate in a radius range of 145mm to 149mm from the center 9 of the substrate, in 0.1mm increments (8 in Figure 2(G)). Figure 2(H) shows the average film thickness plot 10 on the Bare-Si substrate and the average film thickness plot 11 on the HMDS substrate. As shown here, the point where the average film thickness becomes 0 was defined as the film edge 12, and the difference in the film edge position between the Bare-Si substrate and the HMDS-treated substrate was confirmed as the edge recession distance 13. The results are shown in Table 8. A smaller edge recession distance 13 is considered to indicate better coating performance on the HMDS substrate.

[0199] [Table 8]

[0200] As shown in Table 8, the resist underlayer material of the present invention exhibits an edge recession distance of approximately 0.2 mm or less, confirming that the combination of a crosslinking agent containing phenolic hydroxyl groups and a base generator effectively suppresses film edge recession. In Comparative Examples 2-1 to 2-3 and 2-9, which did not contain the combination of a crosslinking agent containing phenolic hydroxyl groups and a base generator, the film edge recession on the HMDS-treated substrate was very large, and the film edge could not be detected within the measurement range. On the other hand, in Comparative Examples 2-4 to 2-6, which contained a phenolic hydroxyl group-containing compound, and Comparative Examples 2-7 and 2-8, which contained a polymer, no film edge recession occurred.

[0201] Example 3: Evaluation of Embedding Characteristics (Examples 3-1 to 3-23, Comparative Examples 3-1 to 3-9) The resist underlayer materials prepared above (UDL-1 to 23, comparative UDL-1 to 9) were each coated onto SiO2 wafer substrates having a dense hole pattern (hole diameter 0.16 μm, hole depth 0.50 μm, distance between the centers of two adjacent holes 0.32 μm), and fired at 250°C for 60 seconds to form a resist underlayer. The substrate used was a base substrate 14 (SiO2 wafer substrate) having a dense hole pattern as shown in Figure 3(I) (overhead view) and (J) (cross-sectional view). The cross-sectional shape of each obtained wafer substrate was observed using a scanning electron microscope (SEM) to confirm whether the holes were filled with the resist underlayer 15 without any voids (gaps). The results are shown in Table 9. When a resist underlayer material with inferior filling characteristics was used, voids were generated inside the holes in this evaluation. When a resist underlayer material with good embedding properties is used, the resist underlayer is filled into the holes without voids in this evaluation, as shown in Figure 3(K).

[0202] [Table 9]

[0203] As shown in Table 9, all of the resist underlayer materials of the present invention were found to be capable of filling hole patterns without voids and exhibiting excellent embedding characteristics. On the other hand, in Comparative Examples 3-7 and 3-8, embedding defects occurred, which are thought to be due to insufficient thermal fluidity because they contain high molecular weight polymers.

[0204] Example 4: Evaluation of Planarization Characteristics (Examples 4-1 to 4-23, Comparative Examples 4-1 to 4-9) The resist underlayer materials prepared above (UDL-1 to 23, comparative UDL-1 to 9) were each coated onto a substrate 16 (SiO2 wafer substrate) having a large isolated trench pattern (Figure 4(L), trench width 10 μm, trench depth 0.1 μm), fired at 250°C for 60 seconds, and the step difference in the resist underlayer 17 between the trenched and non-trenched areas (delta 17 in Figure 4(M)) was observed using a Park Systems NX10 atomic force microscope (AFM). The results are shown in Table 10. In this evaluation, a smaller step difference indicates better planarization characteristics. Note that in this evaluation, a trench pattern with a depth of 0.10 μm was planarized using a resist underlayer material with a film thickness of approximately 0.2 μm, which is a strict evaluation condition for evaluating the superiority or inferiority of the planarization characteristics.

[0205] [Table 10]

[0206] As shown in Table 10, the resist underlayer material of the present invention exhibits superior planarization characteristics, with a smaller step difference between the trench and non-trench portions of the resist underlayer compared to Comparative Examples 4-7 and 4-8, which contain high molecular weight polymers. Furthermore, when comparing the remaining percentage of phenolic hydroxyl groups, Example 4-6, with a remaining percentage of less than 2% (0%), shows superior planarization characteristics compared to Comparative Examples 4-4 to 4-6, with remaining percentages of 3.9% to 27.4%. Moreover, among Comparative Examples 4-4 to 4-6, the lower the remaining percentage of phenolic hydroxyl groups, the higher the planarization performance. This confirms that structures without phenolic hydroxyl groups exhibit high fluidity and high planarization improvement performance.

[0207] Example 5: Pattern formation test (Examples 5-1 to 5-23, Comparative Examples 5-1 to 5-9) UDL-1 to 23 and Comparative Examples UDL-1 to 9, prepared as described above, were applied to an SiO2 substrate having a trench pattern (trench width 10 μm, trench depth 0.10 μm) on which an HMDS-treated SiO2 film with a thickness of 200 nm was formed. A resist underlayer film was formed by baking at 250°C for 60 seconds in air on a bare Si substrate to a thickness of 200 nm. A silicon-containing resist interlayer material (SOG-1) was applied on top of this and baked at 220°C for 60 seconds to form a resist interlayer film with a thickness of 35 nm. A resist toplayer material (SL resist for ArF) was applied and baked at 105°C for 60 seconds to form a resist toplayer film with a thickness of 100 nm. An immersion protective film (TC-1) was applied to the resist toplayer film and baked at 90°C for 60 seconds to form a protective film with a thickness of 50 nm.

[0208] The resist upper layer material (SL resist for ArF) was prepared by dissolving a polymer (RP1), an acid generator (PAG1), and a basic compound (Amine1) in the proportions shown in Table 11 in a solvent containing 0.1% by mass of FC-430 (manufactured by Sumitomo 3M Co., Ltd.), and filtering the mixture through a 0.1 μm fluororesin filter.

[0209] [Table 11]

[0210] The structural formulas of the polymer (RP1), acid generator (PAG1), and basic compound (Amine1) used are shown below. [ka]

[0211] The immersion protective film material (TC-1) was prepared by dissolving the protective film polymer (PP1) in an organic solvent in the proportions shown in Table 12 and filtering it through a 0.1 μm fluororesin filter.

[0212] [Table 12]

[0213] The structural formula of the polymer used (PP1) is shown below. [ka]

[0214] For the silicon-containing resist interlayer material (SOG-1), a polymer represented by ArF silicon-containing interlayer polymer (SiP1) and a crosslinking catalyst (CAT1) were dissolved in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 13, and the mixture was filtered through a fluororesin filter with a pore size of 0.1 μm to prepare the silicon-containing resist interlayer material (SOG-1).

[0215] [Table 13]

[0216] The structural formulas of the ArF silicon-containing interlayer polymer (SiP1) and crosslinking catalyst (CAT1) used are shown below. [ka]

[0217] Next, the samples were exposed using an ArF immersion lithography system (Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.65, 35-degree dipole s polarized illumination, 6% halftone phase shift mask) while varying the exposure dose. The samples were then baked (PEB) at 100°C for 60 seconds and developed with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to obtain a positive-type line-and-space pattern with a pitch of 100 nm and a resist linewidth of 50 nm 1:1.

[0218] Next, using the Telius etching system manufactured by Tokyo Electron, a silicon-containing interlayer was processed using a resist pattern obtained by dry etching as a mask, a lower layer was processed using the silicon-containing interlayer as a mask, and an SiO2 film was processed using the lower layer as a mask.

[0219] The etching conditions are as follows:

[0220] Transfer conditions for resist patterns to SOG films. Chamber pressure: 10.0 Pa RF Power: 1,500W CF4 gas flow rate: 15 sccm O2 gas flow rate: 75 sccm Time: 15sec

[0221] Conditions for transferring SOG film patterns to the underlying film. Chamber pressure: 2.0 Pa RF Power: 500W Ar gas flow rate: 75 sccm O2 gas flow rate: 45 sccm Time: 120sec

[0222] Transfer conditions for the underlying film pattern to the SiO2 film. Chamber pressure: 2.0 Pa RF Power: 2,200W C5F 12 Gas flow rate: 20 sccm C2F6 gas flow rate: 10 sccm Ar gas flow rate: 300 sccm O2 gas flow rate: 60 sccm Time: 90sec

[0223] The cross-sections of the patterns were observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd., and their shapes were compared and summarized in Table 14.

[0224] [Table 14]

[0225] As shown in Table 14, the resist underlayer material of the present invention (Examples 5-1 to 5-23) showed that in all cases the resist upper layer pattern was successfully transferred to the substrate, confirming that the resist underlayer material of the present invention is suitable for use in microfabrication using the multilayer resist method. On the other hand, in Comparative Examples 5-1, 5-2, 5-3, and 5-9, as shown in the film formation evaluation results of Example 1, pinholes generated during film formation caused pattern collapse during pattern processing, making it impossible to form a pattern. In Comparative Examples 5-7 and 5-8, as shown in Examples 3 and 4, the embedding and planarization characteristics were poor, resulting in pattern collapse during pattern processing and making it impossible to form a pattern.

[0226] From the above, it has become clear that the resist underlayer material of the present invention is extremely useful as an organic film material for use in multilayer resist methods because it has good film formation properties and excellent embedding / planarization characteristics. Furthermore, it has become clear that the pattern formation method of the present invention using this material can form fine patterns with high precision even on substrates that have steps. Moreover, the resist underlayer material of the present invention does not need to contain an acid generator, thus avoiding problems such as pattern defects caused by the decomposition products of the acid generator, and maximizing the effect of the base generator.

[0227] This specification includes the following inventions:

[0228] [1]: A resist underlayer material characterized by comprising (A) a compound that does not contain phenolic hydroxyl groups, or a compound that is modified with phenolic hydroxyl groups and has a residual rate of less than 2% of the phenolic hydroxyl groups, wherein the weight-average molecular weight of the compound on a polystyrene basis determined by gel permeation chromatography is 2,500 or less; (B) a crosslinking agent containing a phenolic hydroxyl group represented by the following general formula (1); (C) a base generator; and (D) an organic solvent. [ka] (In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. R 16 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. q is an integer of 1 to 5.)

[0229] [2]: The resist underlayer film material according to [1] above, wherein the (C) base generator is a compound that exhibits basicity by thermal decomposition.

[0230] [3]: The resist underlayer film material according to [1] or [2] above, wherein the (C) base generator is any one of the following general formulas (2), (3) and (4).

Chemical formula

[0231] [4]: X in the above general formulas (2), (3) and (4) - The resist underlayer material according to [3] above, characterized in that it has a structure represented by any of the following general formulas (5), (6), and (7), and is one of the anions selected from the group consisting of chloride ions, bromide ions, iodide ions, fluoride ions, cyanide ions, nitrate ions, and nitrite ions. [ka] (In the above formula, R 10 R represents a linear, branched, or cyclic alkyl, alkenyl, aralkyl, or aryl group having 1 to 20 carbon atoms, which may include an ether group, ester group, or carbonyl group, and the hydrogen atoms of these groups may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. 11 R represents an aryl group having 1 to 20 carbon atoms. The hydrogen atoms of the aryl group may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. 12 , R 13 , R 14 Each of these independently represents a hydrogen atom, a halogen atom other than a fluorine atom, or a linear, branched, or cyclic alkyl, alkenyl, aralkyl, or aryl group having 1 to 20 carbon atoms, which may also contain an ether group, an ester group, or a carbonyl group, and the hydrogen atoms of these groups may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups.12 , R 13 , R 14 Two or more of these may be bonded together to form a ring.

[0232] [5]: X in the above general formulas (2), (3) and (4) - The resist underlayer material according to [3] or [4] above, characterized in that the boiling point of the conjugate acid XH is 200°C or lower.

[0233] [6]: The resist underlayer material according to any one of [1] to [5] above, characterized in that the compound (A) is represented by the following general formula (8). [ka] (In the formula, W is an n-valent organic group having 2 to 50 carbon atoms. n is an integer from 2 to 10, and Y is independently one of the structures shown in the general formula (9) below.) [ka] (In the formula, the dashed line represents the bond site to W. Z is one or more terminal groups, and at least one of the terminal groups is one of the groups shown in the following general formula (10).) [ka] (In the equation, dashed lines represent connections.)

[0234] [7]: The resist underlayer material according to [6] above, characterized in that Z in the general formula (9) is composed of one or more of the groups represented by the general formula (10) and one or more of the groups represented by the following general formulas (11) and (12). [ka] (R in equation (11) above) p R represents a linear, branched, saturated, or unsaturated hydrocarbon group having 1 to 30 carbon atoms, which may be substituted with heteroatoms or may have heteroatoms interposed. qR represents a hydrogen atom or a linear, branched, saturated, or unsaturated hydrocarbon group having 1 to 10 carbon atoms. r The terms represent linear or branched hydrocarbon groups, halogen atoms, nitro groups, amino groups, nitrile groups, alkoxycarbonyl groups, and alkanoyloxy groups with 1 to 10 carbon atoms. m1 represents 0 to 2, m2 and m3 represent the number of substituents on the aromatic ring, m2 and m3 represent integers from 0 to 7, and m2 + m3 satisfies the relationship between 0 and 7. If a is the proportion of the structure of general formula (10) constituting Z, and b is the proportion of the total structure of general formulas (11) and (12), then the relationships a + b = 1.0, 0.50 ≤ a ≤ 0.99, and 0.01 ≤ b ≤ 0.50 are satisfied.

[0235] [8]: The resist underlayer material according to [6] or [7] above, characterized in that W in the general formula (8) has a structure represented by any of the following formulas. [ka] [ka] (In the equation, dashed lines represent connections.)

[0236] [9]: The resist underlayer material according to any one of [1] to [8] above, characterized in that the (D) organic solvent is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher.

[0237]

[10] : The resist underlayer material according to any of [1] to [9] above, further characterized by containing one or more of (E) surfactants, (F) plasticizers, and (G) dyes.

[0238]

[11] : A method for forming a pattern on a substrate to be processed, comprising: (I-1) a step of forming a resist underlayer film by applying a resist underlayer film material described in any of [1] to

[10] above onto a substrate to be processed and then heat-treating it; (I-2) a step of forming a resist upper layer film on the resist underlayer film using a photoresist material; (I-3) a step of pattern exposure of the resist upper layer film and then developing it with a developer to form a pattern on the resist upper layer film; (I-4) a step of transferring a pattern to the resist underlayer film by dry etching using the resist upper layer film on which the pattern has been formed as a mask; and (I-5) a step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed.

[0239]

[12] : A method for forming a pattern on a substrate to be processed, comprising: (II-1) forming a resist underlayer film by applying a resist underlayer film material described in any of [1] to

[10] above onto a substrate to be processed and then heat-treating it; (II-2) forming a resist interlayer film on the resist underlayer film; (II-3) forming a resist upper layer film on the resist interlayer film using a photoresist material; (II-4) forming a pattern on the resist upper layer film by pattern exposure and then developing it with a developer solution; (II-5) transferring the pattern to the resist interlayer film by dry etching using the resist upper layer film on which the pattern has been formed as a mask; (II-6) transferring the pattern to the resist underlayer film by dry etching using the resist interlayer film on which the pattern has been transferred as a mask; and (II-7) processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed.

[0240]

[13] : A method for forming a pattern on a substrate to be processed, comprising: (III-1) forming a resist underlayer film by applying a resist underlayer film material described in any of [1] to

[10] above onto the substrate to be processed and then heat-treating it; (III-2) forming an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the resist underlayer film; (III-3) forming an organic thin film on the inorganic hard mask interlayer film; (III-4) forming a resist upper layer film on the organic thin film using a photoresist material; and (III-5) patterning the resist upper layer film. A pattern formation method characterized by comprising the steps of: (III-6) developing the resist upper layer with a developer after exposure to light to form a pattern on the resist upper layer; (III-7) using the resist upper layer on which the pattern has been formed as a mask to transfer the pattern to the organic thin film and the inorganic hard mask interlayer by dry etching; (III-8) using the inorganic hard mask interlayer on which the pattern has been transferred as a mask to transfer the pattern to the resist lower layer by dry etching; and (III-8) processing the substrate to be processed using the resist lower layer on which the pattern has been formed as a mask to form a pattern on the substrate to be processed.

[0241]

[14] : The pattern formation method according to

[13] above, characterized in that the inorganic hard mask interlayer is formed by CVD or ALD.

[0242]

[15] : The pattern formation method according to any one of

[11] to

[14] above, characterized in that the substrate to be processed is a substrate having a structure or step with a height of 30 nm or more.

[0243]

[16] : The pattern forming method according to any one of

[11] to

[15] above, characterized in that a substrate having a static contact angle with water of 50° or more is used as the substrate to be processed.

[0244]

[17] : A method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of a semiconductor device, characterized in that a resist underlayer film material described in any of [1] to

[10] above is applied by rotation onto a substrate to be processed, and the substrate on which the resist underlayer film material is applied is heat-treated at a temperature of 100°C to 600°C for a range of 10 to 600 seconds to cure and form a resist underlayer film.

[0245]

[18] : A method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of a semiconductor device, characterized in that a resist underlayer film material described in any of [1] to

[10] above is applied by rotation onto a substrate to be processed, and the substrate on which the resist underlayer film material is applied is heat-treated in an atmosphere with an oxygen concentration of 1 volume% to 21 volume% to cure and form a resist underlayer film.

[0246]

[19] : A method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of a semiconductor device, characterized in that a resist underlayer film material described in any of [1] to

[10] above is applied by rotation onto a substrate to be processed, and the substrate on which the resist underlayer film material is applied is heat-treated in an atmosphere with an oxygen concentration of less than 1 volume% to cure and form a resist underlayer film.

[0247]

[20] : The resist underlayer film formation method according to any one of

[17] to

[19] above, characterized in that the substrate to be processed is a substrate having a structure or step with a height of 30 nm or more.

[0248]

[21] : The resist underlayer film formation method according to any one of

[17] to

[20] above, characterized in that a substrate having a static contact angle with water of 50° or more is used as the substrate to be processed.

[0249] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention. [Explanation of Symbols]

[0250] 1...Substrate, 2...Workpiece layer, 2a...Pattern formed on the workpiece layer 3…Resist underlayer, 3a…Resist underlayer pattern, 4…Resist interlayer 4a... Resist interlayer pattern, 5... Resist top layer, 5a...Resist upper layer pattern, 6...Required area (exposed area), 7…Substrate with resist underlayer coating, 8…Film thickness measurement locations (4 locations), 9…Center of the substrate, 10…Average film thickness plot on the bare-Si substrate. 11…Average film thickness plot on HMDS substrate, 12…Film edge, 13…Edge recession distance, 14…Substrate with densely packed hole pattern, 15…Resist underlayer film, 16…Underlayer substrate with large isolated trench pattern, 17…Resist underlayer film, Delta 17…The difference in height between the trenched and non-trenched areas of the resist underlayer.

Claims

1. (A) Compounds that do not contain phenolic hydroxyl groups, or compounds in which phenolic hydroxyl groups are modified and the remaining percentage of said phenolic hydroxyl groups is less than 2%, and the weight-average molecular weight of said compound in terms of polystyrene, determined by gel permeation chromatography, is 2,500 or less. (B) A crosslinking agent containing a phenolic hydroxyl group represented by the following general formula (1), (C) Base generator, and (D) Organic solvents It includes, and, A resist underlayer material characterized in that the compound (A) is represented by the following general formula (8). 【Chemistry 1】 (In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. １６ (where is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms; q is an integer from 1 to 5.) 【Chemistry 2】 (In the formula, W is an n-valent organic group having 2 to 50 carbon atoms. n is an integer from 2 to 10, and Y is independently one of the structures shown in the general formula (9) below.) 【Transformation 3】 (In the formula, the dashed line represents the bond site to W. Z is one or more terminal groups, and at least one of the terminal groups is one of the groups shown in the following general formula (10).) 【Chemistry 4】 (In the equation, dashed lines represent connections.)

2. The resist underlayer material according to claim 1, characterized in that the (C) base generating agent is a compound that exhibits basicity by thermal decomposition.

3. The resist underlayer material according to claim 2, characterized in that the (C) base generator is any of the following general formulas (2), (3), and (4). 【Transformation 5】 (In the above formula, R ０１ ~R ０３ each independently represents a linear, branched or cyclic alkyl or alkenyl group having 1 to 10 carbon atoms which may be substituted with a hetero atom and may have a hetero atom intervening therein, or an aryl or aralkyl group having 6 to 18 carbon atoms which may be substituted with a hetero atom and may have a hetero atom intervening therein. Also, any two of R ０１ , R ０２ and R ０３ may be bonded to each other to form a ring together with the sulfur atom in the formula. X － represents an organic or inorganic anion that serves as a counter ion. However, X － does not include OH － . R ０４ and R ０５ each independently represents an aryl group having 6 to 20 carbon atoms which may be substituted with a hetero atom and may have a hetero atom intervening therein, and a part or all of the hydrogen atoms thereof may be substituted with a linear, branched or cyclic alkyl or alkoxy group having 1 to 10 carbon atoms. Also, R ０４ and R ０５ may be bonded to each other to form a ring together with the iodine atom in the formula. R ０６ , R ０７ , R ０８ and R ０９ each independently represents a hydrogen atom, or a linear, branched or cyclic alkyl, alkenyl or aralkyl group having 1 to 20 carbon atoms which may be substituted with a hetero atom and may have a hetero atom intervening therein, or an aryl or aralkyl group having 6 to 18 carbon atoms which may be substituted with a hetero atom and may have a hetero atom intervening therein. Also, any two or more of R ０６ , R ０７ , R ０８ and R ０９ may be bonded to each other to form a ring together with the nitrogen atom in the formula.)

4. X in the above general formulas (2), (3), and (4) － The resist underlayer material according to claim 3, characterized in that it has a structure represented by any of the following general formulas (5), (6), and (7), and is one of the anions selected from the group consisting of chloride ions, bromide ions, iodide ions, fluoride ions, cyanide ions, nitrate ions, and nitrite ions. 【Transformation 6】 (In the above formula, R １０ R represents a linear, branched, or cyclic alkyl, alkenyl, aralkyl, or aryl group having 1 to 20 carbon atoms, which may include an ether group, ester group, or carbonyl group, and the hydrogen atoms of these groups may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. １１ R represents an aryl group having 1 to 20 carbon atoms. The hydrogen atoms of the aryl group may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. １２ , R １３ , R １４ Each of these independently represents a hydrogen atom, a halogen atom other than a fluorine atom, or a linear, branched, or cyclic alkyl, alkenyl, aralkyl, or aryl group having 1 to 20 carbon atoms, which may also contain an ether group, an ester group, or a carbonyl group, and the hydrogen atoms of these groups may be substituted with one or more halogen atoms, hydroxyl groups, carboxyl groups, amino groups, or cyano groups. １２ , R １３ , R １４ Two or more of these may be bonded together to form a ring.

5. X in the above general formulas (2), (3), and (4) － The resist underlayer material according to claim 4, characterized in that the boiling point of the conjugate acid X-H is 200°C or lower.

6. The resist underlayer material according to claim 1, characterized in that Z in the general formula (9) is composed of one or more of the groups represented by the general formula (10) and one or more of the groups represented by the following general formulas (11) and (12). 【Transformation 7】 (R in formula (11) above) ｐ R represents a linear, branched, saturated, or unsaturated hydrocarbon group having 1 to 30 carbon atoms, which may be substituted with heteroatoms or may have heteroatoms interposed. ｑ R represents a hydrogen atom or a linear, branched, saturated, or unsaturated hydrocarbon group having 1 to 10 carbon atoms. ｒ The terms represent linear or branched hydrocarbon groups having 1 to 10 carbon atoms, halogen atoms, nitro groups, amino groups, nitrile groups, alkoxycarbonyl groups having 1 to 10 carbon atoms, and alkanoyloxy groups having 1 to 10 carbon atoms. m1 represents 0 to 2, m2 and m3 represent the number of substituents on the aromatic ring, m2 and m3 represent integers from 0 to 7, and m2 + m3 satisfies the relationship between 0 and 7. If a is the proportion of the structure of general formula (10) constituting Z, and b is the proportion of the total structure of general formulas (11) and (12), then the relationships a + b = 1.0, 0.50 ≤ a ≤ 0.99, and 0.01 ≤ b ≤ 0.50 are satisfied.

7. The resist underlayer material according to claim 1, characterized in that W in the general formula (8) is a structure represented by any of the following formulas. 【Transformation 8】 【Chemistry 9】 (In the equation, dashed lines represent connections.)

8. The resist underlayer material according to claim 1, characterized in that the (D) organic solvent is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher.

9. The resist underlayer material according to claim 1, further characterized in that it contains one or more of (E) surfactants, (F) plasticizers, and (G) dyes.

10. A method for forming a pattern on a substrate to be processed, (I-1) A step of forming a resist underlayer film by applying a resist underlayer film material according to any one of claims 1 to 9 onto a substrate to be processed, and then heat-treating it. (I-2) A step of forming a resist upper layer film on the resist lower layer film using a photoresist material, (I-3) A step of forming a pattern on the resist upper layer film by pattern exposure followed by development with a developer solution. (I-4) A step of transferring the pattern to the resist underlayer by dry etching using the resist upper layer on which the pattern is formed as a mask, and (I-5) A step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed. A pattern forming method characterized by having the following features.

11. A method for forming a pattern on a substrate to be processed, (II-1) A step of forming a resist underlayer film by applying a resist underlayer film material according to any one of claims 1 to 9 onto a substrate to be processed, and then heat-treating it. (II-2) A step of forming a resist interlayer on the resist underlayer, (II-3) A step of forming a resist upper layer film on the resist interlayer film using a photoresist material, (II-4) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (II-5) A step of transferring the pattern to the resist interlayer by dry etching, using the resist upper layer on which the pattern is formed as a mask. (II-6) A step of transferring the pattern to the resist underlayer film by dry etching using the resist interlayer film on which the pattern has been transferred as a mask, and (II-7) A step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed, A pattern forming method characterized by having the following features.

12. A method for forming a pattern on a substrate to be processed, (III-1) A step of forming a resist underlayer film by applying a resist underlayer film material according to any one of claims 1 to 9 onto a substrate to be processed, and then heat-treating it. (III-2) A step of forming an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the resist underlayer film, (III-3) A step of forming an organic thin film on the inorganic hard mask interlayer, (III-4) A step of forming a resist upper layer film on the organic thin film using a photoresist material, (III-5) A step of forming a pattern on the resist upper layer film by pattern exposure followed by development with a developer solution. (III-6) A step of transferring the pattern to the organic thin film and the inorganic hard mask interlayer film by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (III-7) A step of transferring the pattern to the resist underlayer film by dry etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask, and (III-8) A step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed, A pattern forming method characterized by having the following features.

13. The pattern forming method according to claim 12, characterized in that the inorganic hard mask interlayer is formed by CVD or ALD.

14. The pattern forming method according to claim 10, characterized in that the substrate to be processed is a substrate having a structure or step with a height of 30 nm or more.

15. The pattern forming method according to claim 10, characterized in that a substrate having a static contact angle with water of 50° or more is used as the substrate to be processed.

16. A method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of a semiconductor device, characterized in that a resist underlayer film material according to any one of claims 1 to 9 is rotary coated onto a substrate to be processed, and the substrate coated with the resist underlayer film material is heat-treated at a temperature of 100°C to 600°C for a range of 10 to 600 seconds to cure and form a resist underlayer film.

17. A method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of a semiconductor device, characterized in that a resist underlayer film material according to any one of claims 1 to 9 is rotary coated onto a substrate to be processed, and the substrate coated with the resist underlayer film material is heat-treated in an atmosphere with an oxygen concentration of 1 volume% to 21 volume% to cure and form a resist underlayer film.

18. A method for forming a resist underlayer film that functions as an organic planar film used in the manufacturing process of a semiconductor device, characterized in that a resist underlayer film material according to any one of claims 1 to 9 is rotary coated onto a substrate to be processed, and the substrate coated with the resist underlayer film material is heat-treated in an atmosphere with an oxygen concentration of less than 1 volume% to cure and form a resist underlayer film.

19. The resist underlayer film formation method according to claim 16, characterized in that the substrate to be processed is a substrate having a structure or step with a height of 30 nm or more.

20. The resist underlayer film formation method according to claim 16, characterized in that a substrate having a static contact angle with water of 50° or more is used as the substrate to be processed.

Images