Compound for forming metal-containing film, composition for forming metal-containing film, and patterning process

Abstract

To provide: a compound for forming a metal-containing film that yields a resist middle layer film making it possible to obtain a favorable pattern shape and having high adhesiveness to a resist upper layer film to prevent collapse of a fine pattern in a fine patterning process in a semiconductor device manufacturing process; a composition for forming a metal-containing film using the compound; and a patterning process using the composition.SOLUTION: A compound for forming a metal-containing film contains: at least one metal atom selected from a group consisting of Ti, Zr and Hf; and a multidentate ligand coordinated to the metal atom and comprising a cyclic ether structure having 2 to 13 carbon atoms.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a compound for forming a metal-containing film that can be used for fine patterning by a multilayer resist method in a semiconductor device manufacturing process, a composition for forming a metal-containing film using the compound, and a pattern formation method using the composition. [Background technology]

[0002] As LSIs become more highly integrated and faster, pattern dimensions are becoming finer. Lithography technology has achieved the formation of finer patterns by shortening the wavelength of light sources and selecting appropriate resist compositions to match them, in line with this trend. The core of this technology is a positive photoresist composition used in a single layer. This single-layer positive photoresist composition has a skeleton in the resist resin that is resistant to dry etching using chlorine- or fluorine-based gas plasma, and also has a switching mechanism that dissolves the exposed areas, forming a pattern by dissolving the exposed areas, and then dry etching the substrate using the remaining resist pattern as an etching mask.

[0003] However, when the thickness of the photoresist film used is made finer, that is, when the pattern width is made smaller, the resolution performance of the photoresist film is reduced, and when an attempt is made to develop the photoresist film into a pattern using a developer, the so-called aspect ratio becomes too large, resulting in problems such as pattern collapse. For this reason, photoresist films have been made thinner as patterns become finer.

[0004] On the other hand, in the processing of a substrate to be processed, a method is usually used in which a photoresist film on which a pattern is formed is used as an etching mask to process the substrate by dry etching, but in reality, there is no dry etching method that can obtain perfect etching selectivity between the photoresist film and the substrate to be processed. Therefore, there is a problem that the photoresist film is also damaged and collapsed during processing of the substrate, and the resist pattern cannot be accurately transferred to the substrate to be processed. Therefore, with the miniaturization of patterns, a higher dry etching resistance has been required for the resist composition. However, on the other hand, in order to increase the resolution, a resin with low light absorption at the exposure wavelength has been required for the resin used in the photoresist composition. Therefore, as the exposure light has become shorter in wavelength from i-line to KrF and ArF, the resin has also changed to novolac resin, polyhydroxystyrene, and resin with an aliphatic polycyclic skeleton, but in reality, the etching speed under dry etching conditions during substrate processing has become faster, and recent photoresist compositions with high resolution tend to have weaker etching resistance.

[0005] For this reason, it has become necessary to dry etch the substrate to be processed using a thinner photoresist film with a weaker etching resistance, and securing the materials and processes for this processing step has become an urgent need.

[0006] One method for solving such problems is the multi-layer resist method, in which a resist intermediate film having etching selectivity different from that of a photoresist film (i.e., a resist upper layer film) is interposed between the resist upper layer film and a substrate to be processed, a pattern is obtained in the resist upper layer film, and then the pattern is transferred to the resist intermediate film by dry etching using the resist upper layer film pattern as a dry etching mask, and the pattern is further transferred to the substrate to be processed by dry etching using the resist intermediate film as a dry etching mask.

[0007] One of the multilayer resist methods is a three-layer resist method that can be performed using a general resist composition used in a single-layer resist method. In this three-layer resist method, for example, an organic film made of novolac resin or the like is formed on a substrate to be processed as a resist underlayer film, a silicon-containing resist intermediate film is formed on the organic film as a resist intermediate film, and a normal organic photoresist film is formed on the organic film as a resist upper layer film. When dry etching is performed using fluorine-based gas plasma, the organic resist upper layer film has a good etching selectivity to the silicon-containing resist intermediate film, so that the resist upper layer film pattern can be transferred to the silicon-containing resist intermediate film by dry etching using fluorine-based gas plasma. According to this method, even if a resist composition that is difficult to form a pattern with a sufficient film thickness for directly processing a substrate to be processed or a resist composition that does not have sufficient dry etching resistance for processing a substrate is used, a pattern can be transferred to the silicon-containing resist intermediate film (resist intermediate film), and then, by performing pattern transfer by dry etching using oxygen-based or hydrogen-based gas plasma, a pattern of an organic film (resist underlayer film) made of novolac resin or the like that has sufficient dry etching resistance for processing a substrate can be obtained. As the above-mentioned resist underlayer film, many films are already known, for example, the one described in Patent Document 1.

[0008] As the silicon-containing resist intermediate film used in the above-mentioned three-layer resist method, silicon-containing inorganic films by CVD, such as SiO2 film (e.g., Patent Document 2) and SiON film (e.g., Patent Document 3), and as films obtained by spin coating, SOG (spin-on glass) films (e.g., Patent Document 4, Non-Patent Document 1) and crosslinked silsesquioxane films (e.g., Patent Document 5) are used, and polysilane films (e.g., Patent Document 6) may also be used. Among these, SiO2 film and SiON film have high performance as a dry etching mask when dry etching the underlying organic film, but require special equipment for film formation. In contrast, SOG film, crosslinked silsesquioxane film, and polysilane film can be formed only by spin coating and heating, and are considered to have high process efficiency.

[0009] The silicon-containing films that have been used conventionally in such multilayer resist methods have some problems. For example, when a resist pattern is formed by photolithography, it is well known that the exposure light is reflected by the substrate and interferes with the incident light, causing the so-called standing wave problem. In order to obtain a fine pattern without edge roughness of the resist film under the state-of-the-art ArF immersion and high NA exposure conditions, an anti-reflection function is essential as an intermediate film. Furthermore, in the state-of-the-art semiconductor processes such as those mentioned above, the photoresist is becoming thinner, so the intermediate film is also required to be thinner, and in the next-generation exposure process, it is required to impart an anti-reflection effect with a film thickness of 30 nm or less. In addition, it is preferable that the dry etching rate for oxygen gas plasma, which is generally used when processing the resist underlayer film, is smaller in order to increase the etching selectivity between the intermediate film and the underlayer film, and the trend toward thinner films requires the intermediate film to have improved dry etching resistance.

[0010] Metal hard mask films containing Ti or Zr have been attracting attention as a resist intermediate film that meets the requirements for anti-reflection effect and dry etching properties, instead of conventional silicon-containing films. TiO2 and ZrO2 are known as high refractive index materials, and by including them in the film, it is possible to improve the anti-reflection effect under high NA exposure conditions. In addition, by including metal-oxygen bonds, excellent dry etching resistance against oxygen gas can be expected.

[0011] In addition, since metal hard mask films have excellent resistance to dry etching not only with oxygen gas but also with fluorine gas, they are also promising for use in a two-layer resist method in which a metal hard mask film is formed on the workpiece substrate as a resist underlayer film, and then an upper resist layer is formed on top of that.

[0012] On the other hand, when such a metal hard mask film is used directly under a resist top layer, improving adhesion with the resist pattern becomes an issue. The hardened metal hard mask film has a much higher surface energy (or a smaller water contact angle) than the subsequently applied photoresist. Such a mismatch in surface energy causes poor adhesion between the metal hard mask film and the subsequently applied photoresist, resulting in pattern collapse.

[0013] In order to suppress the collapse of the photoresist pattern on the metal hard mask film, the surface modification of the metal hard mask film is necessary. For example, Patent Document 7 reports a metal hard mask containing a surface-modified organic polymer. It has been reported that the adhesion to the resist pattern is improved by utilizing the difference in free energy between the organic polymer and the metal compound and distributing the organic polymer unevenly on the surface layer. In order to suppress the pattern collapse, an organic polymer containing a surface treatment portion selected from hydroxyl, protected hydroxyl, protected carboxyl, and a mixture thereof is used. However, in the current situation where finer pattern formation is required, it cannot be said that these materials have sufficient pattern collapse suppression performance. In addition, since the inclusion of an organic polymer may deteriorate the dry etching resistance against oxygen gas, there is a demand for the development of a compound for forming a metal-containing film having excellent adhesion to the resist upper layer film.

[0014] Recently, it is said that the interaction at the interface between the resist top layer film and the underlayer film directly below the resist top layer film in a fine pattern affects the sensitivity of the resist, the shape of the pattern (rectangularity and space residues), etc., and from these perspectives as well, there is a demand for improvement in the performance of the underlayer film directly below the resist top layer film (Non-Patent Document 2). [Prior art documents] [Patent documents]

[0015] [Patent Document 1] JP 2004-205685 A [Patent Document 2] Japanese Patent Application Publication No. 7-183194 [Patent Document 3] Japanese Patent Application Publication No. 7-181688 [Patent Document 4] Japanese Patent Application Publication No. 5-291208 [Patent Document 5] Special Publication No. 2005-520354 [Patent Document 6] Japanese Patent Application Publication No. 11-60735 [Patent Document 7] Patent Publication No. 6463600 [Non-patent literature]

[0016] [Non-Patent Document 1] J.Appl.Polym. Sci.,Vol.88,636-640(2003) [Non-Patent Document 2] Proc. SPIE Vol. 7273,72731J(2009) Summary of the Invention [Problem to be solved by the invention]

[0017] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a compound for forming a metal-containing film that can obtain a good pattern shape in a fine patterning process in a semiconductor device manufacturing process, and that can provide a metal-containing film that has high adhesion to a resist overlying film and prevents collapse of the fine pattern, a composition for forming a metal-containing film using the compound, and a pattern formation method using the composition. [Means for solving the problem]

[0018] In order to solve the above problems, the present invention provides The present invention provides a compound for forming a metal-containing film, which has at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms coordinated to the metal atom.

[0019] When such a compound for forming a metal-containing film is used in a composition for forming a resist underlayer film, it is possible to form a metal-containing film that has high adhesion to a resist upper layer film, has an effect of preventing collapse of a fine pattern, and gives a good pattern shape. In addition, the obtained metal-containing film exhibits a high refractive index, and therefore can exhibit a high antireflection effect under ArF immersion and high NA exposure conditions.

[0020] The polydentate ligand preferably has a structure represented by any one of the following general formulas (1-A) to (1-D). [ka] In the above general formulas (1-A) to (1-D), R1 to R4 are each a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, R5 to R6 are each a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and R7 to R 10 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, R 11 is a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and Y is a divalent organic group having 1 to 10 carbon atoms. The compounds of the above general formulas (1-A) to (1-D) contain at least one or more cyclic ether structures having 2 to 13 carbon atoms. In the above general formula (1-A), R2 and R3 may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms. In the above general formula (1-B), adjacent R5 and R6 may be bonded to each other to form an unsaturated or saturated ring structure. In the above general formula (1-C), adjacent R8 and R9 may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms, or an unsaturated or saturated ring structure.

[0021] By having a multidentate ligand having such a structure, when the metal-containing film-forming compound is used in a composition for forming a resist underlayer film, higher adhesion to the resist upper layer film can be obtained, which is more effective in preventing collapse of the fine pattern.

[0022] In this case, the multidentate ligand preferably has a structure represented by the above formula (1-A) or (1-B).

[0023] Such a polydentate ligand can provide a compound for forming a metal-containing film having excellent stability.

[0024] The cyclic ether structure is preferably any one of structures represented by the following formulas (a-1) to (a-2). [ka] (In the formula, R a is a hydrogen atom or an organic group having 1 to 10 carbon atoms, and * indicates a bond.

[0025] By including such a cyclic ether structure, the epoxy or oxetane structure undergoes a ring-opening reaction during heating to harden the film, and the hydroxyl group generated by this ring-opening reaction also contributes to improving adhesion to the upper layer of the resist.

[0026] In addition, the compound for forming a metal-containing film is preferably a reaction product of a metal-containing compound containing any one of a metal compound represented by the following formula (2), a hydrolysate or condensate of a metal compound represented by the following formula (2), or a hydrolysis condensate, and a multidentate ligand having a structure represented by any one of the above general formulas (1-A) to (1-D). [ka] (In the formula, M is any one of Ti, Zr, and Hf. L is a monodentate ligand and / or a polydentate ligand having 1 to 30 carbon atoms. X is a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, -NR a R b R is a hydrolyzable group selected from the group consisting of a and R b are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; a+b=4, and a and b are integers of 0 to 4.

[0027] By using such a compound for forming a metal-containing film, a metal-containing film having superior resistance to dry etching with oxygen gas can be formed.

[0028] In this case, the metal compound represented by the formula (2) preferably has a structure represented by the following formula (3). [ka] (Wherein, M is Ti, Zr, or Hf; R 1A is a monovalent organic group having 1 to 20 carbon atoms.

[0029] A compound for forming a metal-containing film having such a structure is preferable from the viewpoints of productivity and availability of raw materials.

[0030] In addition, it is preferable that the compound for forming a metal-containing film further contains a ligand derived from a silicon compound represented by the following general formula (4). [ka] (In the above general formula (4), R 3A , R 3B and R 3C is any organic group selected from an organic group having 1 to 30 carbon atoms and a bridging group having any of the structures represented by the following general formulas (b-1) to (b-3), a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and an aryl group having 1 to 20 carbon atoms. [ka] (In the above general formulas (b-1) to (b-3), R3 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q is 0 or 1, and * is a bond.)

[0031] By including such a ligand, the stability of the metal-containing film-forming compound can be further improved.

[0032] In addition, the present invention provides a metal-containing film-forming composition, (A) the metal-containing film-forming compound, and (B) Organic solvent The present invention provides a composition for forming a metal-containing film, which comprises:

[0033] Such a composition for forming a metal-containing film can form a metal-containing film that has high adhesion to a resist top layer film, has the effect of preventing collapse of a fine pattern, and gives a good pattern shape. Furthermore, the obtained metal-containing film exhibits a high refractive index, and therefore can exhibit a high anti-reflection effect under ArF immersion and high NA exposure conditions.

[0034] The composition may also contain one or more of (C) a thermal acid generator and (D) a photoacid generator.

[0035] A composition for forming a metal-containing film that contains the above additives becomes a composition for forming a metal-containing film that is superior in coatability and adhesion to a resist upper layer film.

[0036] The composition may further contain one or more of (E) a crosslinking agent and (F) a surfactant.

[0037] A composition for forming a metal-containing film that contains the above additives is a composition for forming a metal-containing film that has better coatability, dry etching resistance, and filling and / or planarization properties.

[0038] The (B) organic solvent is preferably 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.

[0039] By imparting fluidity to the metal-containing film-forming compound by adding a high-boiling point solvent, the occurrence of coating defects caused by drying of the metal-containing film-forming composition can be suppressed.

[0040] The present invention also provides a method for forming a pattern on a substrate to be processed, comprising the steps of: (I-1) a step of applying the composition for forming a metal-containing film onto a substrate to be processed and then heat-treating the composition to form a metal-containing film; (I-2) forming a resist top layer film on the metal-containing film using a photoresist material; (I-3) a step of forming a pattern on the resist upper layer film by pattern-exposing the resist upper layer film and then developing the resist upper layer film with a developer; (I-4) a step of transferring the pattern to the metal-containing film by dry etching using the resist top layer film on which the pattern is formed as a mask; and (I-5) A step of processing the substrate to be processed using the metal-containing film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. The present invention provides a pattern forming method comprising the steps of:

[0041] The present invention also provides a method for forming a pattern on a substrate to be processed, comprising the steps of: (II-1) forming a resist underlayer film on a substrate to be processed; (II-2) a step of applying the above-mentioned composition for forming a metal-containing film onto the resist underlayer film, and then performing a heat treatment to form a metal-containing film; (II-3) forming a resist top layer film on the metal-containing film using a photoresist material; (II-4) a step of forming a pattern on the resist upper layer film by pattern-exposing the resist upper layer film and then developing the resist upper layer film with a developer; (II-5) a step of transferring the pattern to the metal-containing film by dry etching using the resist upper layer film on which the pattern is formed as a mask; (II-6) a step of transferring a pattern to the resist underlayer film by dry etching using the metal-containing film to which the pattern has been transferred as a mask; (II-7) a step of processing the substrate using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate; The present invention provides a pattern forming method comprising the steps of:

[0042] Thus, the metal-containing film-forming compound of the present invention is, for example, a metal-containing film-forming compound containing a cyclic ether structure selected from the above formula (a-1) or (a-2), and when used in a metal-containing film-forming composition, a metal-containing film having excellent adhesion to a resist upper layer film can be formed, and therefore the compound can be suitably used in various pattern formation methods such as a two-layer resist process and a three-layer resist process. In these pattern formation methods, the metal-containing film provided by the present invention can effectively suppress pattern collapse, making it suitable for photolithography of the resist upper layer film and enabling the resist upper layer film pattern to be transferred to a substrate to be processed with high accuracy. Effect of the Invention

[0043] As described above, the present invention provides a compound for forming a metal-containing film that has high adhesion to a resist overlying film and has an effect of suppressing collapse of a fine pattern, a composition for forming a metal-containing film using the compound, and a pattern formation method using the composition.

[0044] Since the resist underlayer film formed using the conventional metal-containing film-forming compound has a much higher surface energy (or a smaller water contact angle) than the subsequently applied photoresist, such a mismatch in surface energy causes poor adhesion between the metal-containing film and the subsequently applied photoresist, resulting in pattern collapse. In addition, when an organic polymer is mixed as a surface modifier, the dry etching resistance during processing of the organic underlayer film becomes insufficient, which may induce poor pattern transfer.

[0045] In contrast, the metal-containing film-forming compound of the present invention contains a cyclic ether structure, so when used in a metal-containing film-forming composition, a metal-containing film with excellent adhesion to a resist upper layer film can be formed. Therefore, it has an effect of suppressing the collapse of a fine pattern, and also provides a highly rectangular pattern shape of the resist upper layer film to a substrate to be processed, so it is extremely useful in a multi-layer resist process. In addition, the metal-containing film-forming compound using a multidentate ligand of the present invention can form a resist underlayer film with a higher ratio of metal atoms than the metal-containing film-forming compound using a monodentate ligand. Therefore, it has excellent resistance to dry etching using oxygen gas and fluorine gas, and can form a fine pattern with high precision on a substrate to be processed in various pattern formation methods such as a two-layer resist process and a three-layer resist process. [Brief description of the drawings]

[0046] [Figure 1] FIG. 2 is an explanatory diagram of an example (three-layer resist process) of the pattern forming method of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram of an example (two-layer resist process) of the pattern forming method of the present invention. [Diagram 3] 1 is an explanatory diagram of reflectance calculation in a pattern formation method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] As described above, there has been a demand for the development of a metal-containing film-forming compound that can provide a metal-containing film that has high adhesion to a resist overlayer film and prevents collapse of a fine pattern in a fine patterning process in a semiconductor device manufacturing process, a metal-containing film-forming composition that uses the compound, and a pattern formation method that uses the composition.

[0048] As a result of extensive research into the above-mentioned problems, the inventors have found that the above-mentioned problems can be solved by a compound for forming a metal-containing film containing a ligand of a specific structure, a composition for forming a metal-containing film using the compound, and a pattern formation method using the composition, and have thus completed the present invention.

[0049] That is, the present invention relates to a compound for forming a metal-containing film, which has at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms coordinated to the metal atom.

[0050] The present invention will be described in detail below, but the present invention is not limited thereto.

[0051] <Compounds for forming metal-containing films> The present invention relates to a compound for forming a metal-containing film that can be used in a composition for forming a metal-containing film, characterized in that the compound for forming a metal-containing film has at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms coordinated to the metal atom.

[0052] When such a compound for forming a metal-containing film is used in a composition for forming a resist underlayer film, it is possible to form a metal-containing film that has high adhesion to a resist upper layer film, has an effect of preventing collapse of a fine pattern, and gives a good pattern shape. In addition, the obtained metal-containing film exhibits a high refractive index, and therefore can exhibit a high antireflection effect under ArF immersion and high NA exposure conditions.

[0053] The polydentate ligand preferably has any of the structures represented by the following general formulas (1-A) to (1-D). [ka] In the above general formulas (1-A) to (1-D), R1 to R4 are each a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, R5 to R6 are each a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and R7 to R 10 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, R 11 is a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and Y is a divalent organic group having 1 to 10 carbon atoms. The compounds of the above general formulas (1-A) to (1-D) contain at least one or more cyclic ether structures having 2 to 13 carbon atoms. In the above general formula (1-A), R2 and R3 may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms. In the above general formula (1-B), adjacent R5 and R6 may be bonded to each other to form an unsaturated or saturated ring structure. In the above general formula (1-C), adjacent R8 and R9 may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms, or an unsaturated or saturated ring structure.

[0054] The compounds of the above formulas (1-A) to (1-D) contain at least one cyclic ether structure having 2 to 13 carbon atoms, preferably 2 to 10 carbon atoms. It is more preferable that the compound contains one or two such cyclic ether structures, and even more preferable that the compound contains one cyclic ether structure in the molecule.

[0055] In the above formula (1-A), R1 and R4 are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and are preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted allyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, or a monovalent organic group having 1 to 20 carbon atoms which contains a cyclic ether structure having 2 to 13 carbon atoms, and more preferably a methyl group, an ethyl group, a phenyl group, an allyloxy group, a propargyloxy group, an alkoxy group having 1 to 10 carbon atoms, or a monovalent organic group having 1 to 20 carbon atoms which contains a cyclic ether structure having 2 to 13 carbon atoms. When R1 and R4 do not contain a cyclic ether structure having 2 to 13 carbon atoms, they are preferably a methyl group, a methoxy group, or an ethoxy group.

[0056] R2 and R3 are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and are preferably a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted allyl group having 2 to 10 carbon atoms, a substituted or unsubstituted ethynyl group having 2 to 10 carbon atoms, or a monovalent organic group having 1 to 20 carbon atoms which contains a cyclic ether structure having 2 to 13 carbon atoms, and more preferably a hydrogen atom, a methyl group, an ethyl group, a phenyl group, an allyloxy group, a propargyloxy group, or a monovalent organic group having 1 to 20 carbon atoms which contains a cyclic ether structure having 2 to 13 carbon atoms. R2 and R3 may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms. When R2 has a substituent other than a hydrogen atom, R3 is preferably a hydrogen atom. It is preferable that at least one of R2 and R3 is a hydrogen atom. When R2 and R3 do not contain a cyclic ether structure having 2 to 13 carbon atoms, it is preferable that both R2 and R3 are hydrogen atoms.

[0057] In the above formula (1-B), R5 and R6 are hydrogen atoms or monovalent organic groups having 1 to 20 carbon atoms that may contain a cyclic ether structure having 2 to 13 carbon atoms, and are preferably hydrogen atoms, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted aryl groups having 6 to 20 carbon atoms, substituted or unsubstituted allyl groups having 2 to 10 carbon atoms, substituted or unsubstituted ethynyl groups having 2 to 10 carbon atoms, or monovalent organic groups having 1 to 20 carbon atoms that contain a cyclic ether structure having 2 to 13 carbon atoms. When no cyclic ether structure having 2 to 13 carbon atoms is contained, R5 and R6 are preferably hydrogen atoms. R5 and R6 may be bonded to each other to form an unsaturated or saturated ring structure.

[0058] In the above formula (1-C), R7 and R 10 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, is preferably a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, and is more preferably a hydrogen atom.

[0059] In the above formula (1-C), R8 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and more preferably a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms. R9 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and more preferably a hydrogen atom or an alkyl group or aryl group having 1 to 10 carbon atoms, and even more preferably a hydrogen atom. R8 and R9 may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms, or an unsaturated or saturated ring structure.

[0060] In the above formula (1-D), R 11 is preferably a divalent organic group having 1 to 20 carbon atoms containing a cyclic ether structure having 2 to 13 carbon atoms. Y is a divalent organic group having 1 to 10 carbon atoms, preferably a divalent hydrocarbon group having 1 to 10 carbon atoms, and from the viewpoint of availability of raw materials, more preferably a hydrocarbon group having 1 to 5 carbon atoms, further preferably a methylene group or ethylene group, and particularly preferably an ethylene group.

[0061] By having such a multidentate ligand, when the metal-containing film-forming compound is used in a composition for forming a resist underlayer film, higher adhesion to the resist upper layer film can be obtained, which is more effective in preventing collapse of the fine pattern.

[0062] The cyclic ether structure (a cyclic ether structure having 2 to 13 carbon atoms) is preferably any one of structures represented by the following formulas (a-1) to (a-2). [ka] (In the formula, R a is a hydrogen atom or an organic group having 1 to 10 carbon atoms, and * indicates a bond.

[0063] In the case of such a metal-containing film-forming compound, the epoxy or oxetane structure undergoes a ring-opening reaction during heating to harden the film, and the hydroxyl group generated by this ring-opening reaction also contributes to improving adhesion to the upper layer of the resist.

[0064] R in (a-2) above a is preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably an ethyl group.

[0065] Examples of the structures of the ligands derived from formulae (1-A) to (1-D) include the compounds shown below, but the present invention is not limited to these.

[0066] [ka] (Above R1, R4, R a is the same as above, and n represents 1 to 10.)

[0067] From the viewpoint of productivity and stability of the metal-containing film-forming compound, the cyclic ether structure is more preferably a structure represented by formula (a-2).

[0068] The polydentate ligand more preferably has a structure represented by the above formula (1-A) or (1-B).

[0069] Such a polydentate ligand can provide a compound for forming a metal-containing film having excellent stability.

[0070] In addition, the compound for forming a metal-containing film is preferably a reaction product of (a) a metal-containing compound including any one of a metal compound represented by the following formula (2), a hydrolysate or condensate of a metal compound represented by the following formula (2), or a hydrolysis condensate, and a multidentate ligand having a structure represented by any one of the above general formulas (1-A) to (1-D). [ka] (In the formula, M is any one of Ti, Zr, and Hf. L is a monodentate ligand and / or a polydentate ligand having 1 to 30 carbon atoms. X is a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, -NR a R b R is a hydrolyzable group selected from the group consisting of a and R b are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; a+b=4, and a and b are integers of 0 to 4.

[0071] When such a compound for forming a metal-containing film is used in a composition for forming a metal-containing film, a metal-containing film having excellent resistance to dry etching with oxygen gas can be formed.

[0072] [(a) Metal-containing compounds] (hydrolyzable group) Examples of the hydrolyzable group X in the above formula (2) include a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, and -NR a R b Examples include: R a and R b is preferably each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0073] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0074] Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, and a t-butoxy group.

[0075] Examples of the carboxylate group include an acetate group, a propionate group, a butyrate group, an n-hexanecarboxylate group, and an n-octanecarboxylate group.

[0076] Examples of the acyloxy group include an acetoxy group, an ethyloxy group, a propionyloxy group, a butyryloxy group, a t-butyryloxy group, a t-amylyloxy group, an n-hexanecarbonyloxy group, and an n-octanecarbonyloxy group.

[0077] Above -NR a R b Examples of the amino group include an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, and a dipropylamino group.

[0078] The hydrolyzable group X is preferably an alkoxy group, more preferably an i-propoxy group, an n-butoxy group, or a t-butoxy group.

[0079] (monodentate ligand) Examples of the monodentate ligand L in the above formula (2) include a hydroxo ligand, a carboxy ligand, an amide ligand, an amine ligand, an ammonia ligand, and an olefin ligand.

[0080] Examples of the amide ligand include an unsubstituted amide ligand (NH2), a methylamide ligand (NHMe), a dimethylamide ligand (NMe2), a diethylamide ligand (NEt2), and a dipropylamide ligand (NPr2).

[0081] Examples of the amine ligand include pyridine, trimethylamine ligand, and piperidine ligand.

[0082] Examples of the olefin ligand include chain olefins such as ethylene and propylene, and cyclic olefins such as cyclopentene, cyclohexene and norbornene.

[0083] (polydentate ligand) Examples of the multidentate ligand L in the above formula (2) include a ligand derived from a hydroxy acid ester, a ligand derived from a β-diketone, a ligand derived from a β-ketoester, a ligand derived from an α,α-dicarboxylate, a hydrocarbon having a π bond, and a diphosphine.

[0084] Examples of the hydroxy acid ester include glycolic acid ester, lactic acid ester, 2-hydroxycyclohexane-1-carboxylic acid ester, and salicylic acid ester.

[0085] Examples of the β-diketone include acetoacetate, α-alkyl-substituted acetoacetate, β-ketopentanoate, benzoylacetate, and 1,3-acetonedicarboxylate.

[0086] Examples of the α,α-dicarboxylic acid ester include malonic acid diesters, α-alkyl-substituted malonic acid diesters, α-cycloalkyl-substituted malonic acid diesters, and α-aryl-substituted malonic acid diesters.

[0087] Examples of the hydrocarbon having a π bond include chain dienes such as butadiene and isoprene, cyclic dienes such as cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene and norbornadiene, and aromatic hydrocarbons such as benzene, toluene, xylene, hexamethylbenzene, naphthalene and indene.

[0088] Examples of the diphosphine include 1,1-bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl, and 1,1'-bis(diphenylphosphino)ferrocene.

[0089] In the above general formula (2), a+b=4, and a and b are integers of 0 to 4. a is preferably 0 to 3, more preferably 0 to 2, even more preferably 1 or 2, and particularly preferably 2. b is preferably 2 to 4, more preferably 2 or 3, and even more preferably 2. By setting a and b within the above ranges, the stability of the (A) metal compound can be increased.

[0090] Examples of the (a) metal-containing compound include compounds containing titanium, such as diisopropoxybis(2,4-pentanedionato)titanium(IV), tetra n-butoxytitanium(IV), tetra n-propoxytitanium(IV), tri n-butoxymonostearate titanium(IV), titanium(IV) butoxide oligomer, aminopropyltrimethoxytitanium(IV), triethoxymono(2,4-pentanedionato)titanium(IV), tri-n-prop ... Examples of compounds containing zirconium include dibutoxybis(ethylacetoacetate)zirconium(IV), di-n-butoxybis(2,4-pentanedionato)zirconium(IV), tetra-n-butoxyzirconium(IV), tetra-n-propoxyzirconium(IV), tetraisopropoxyzirconium(IV), and tetraisopropoxyzirconium(IV). V), aminopropyltriethoxyzirconium(IV), 2-(3,4-epoxycyclohexyl)ethyltrimethoxyzirconium(IV), γ-glycidoxypropyltrimethoxyzirconium(IV), 3-isocyanopropyltrimethoxyzirconium(IV), triethoxymono(2,4-pentanedionato)zirconium(IV), tri-n-propoxymono(2,4-pentanedionato)zirconium(IV), triisopropoxymono(2,4-pentanedionato) )zirconium(IV), tri(3-methacryloxypropyl)methoxyzirconium(IV), tri(3-acryloxypropyl)methoxyzirconium(IV), and the like. Compounds containing hafnium include diisopropoxybis(2,4-pentanedionato)hafnium(IV), tetrabutoxyhafnium(IV), tetraisopropoxyhafnium(IV), tetraethoxyhafnium(IV), dichlorobis(cyclopentadienyl)hafnium(IV), and the like.

[0091] From the viewpoint of easy availability of raw materials, the metal compound represented by the formula (2) preferably has a structure represented by the following formula (3). [ka] (Wherein, M is Ti, Zr, or Hf; R 1A is a monovalent organic group having 1 to 20 carbon atoms.

[0092] In the formula (3), R 1A represents a monovalent organic group having 1 to 20 carbon atoms, preferably a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, or a t-butyl group, more preferably an isopropyl group, an n-butyl group, or a t-butyl group.

[0093] [(b) Ligand-forming compound] During the synthesis reaction of the compound for forming a metal-containing film, in addition to (a) the metal-containing compound and the polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms, a compound that can become a monodentate or polydentate ligand in the compound for forming a metal-containing film (hereinafter referred to as (b) compound for forming a ligand) may be added.

[0094] Examples of the (b) ligand-forming compound include organic compounds derived from hydroxo ligands, carboxy ligands, amide ligands, amine ligands, ammonia ligands, olefin ligands, etc., which are listed as L in the above formula (2), organic compounds derived from ligands derived from hydroxy acid esters, ligands derived from β-diketones, ligands derived from β-ketoesters, ligands derived from α,α-dicarboxylate esters, etc., as well as compounds having compounds having multiple hydroxy groups.

[0095] Furthermore, the (b) ligand-forming compound may be an organic compound having 1 to 30 carbon atoms and containing at least one crosslinking group represented by any one of the following general formulas (c-1) to (c-4), (d-1) to (d-4), and (e-1) to (e-3).

[0096] [ka] (In the above general formulas (c-1) to (c-4), R c represents a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond. [ka] (In the above general formula, R d1 is a hydrogen atom or a methyl group, which may be the same or different in the same formula, R d2 is a hydrogen atom, or a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * represents a bonding site. [ka] (In the above general formulas (e-1) to (e-3), Y e is a divalent organic group having 1 to 31 carbon atoms, preferably 1 to 20 carbon atoms; R e2 is a hydrogen atom, a substituted or unsubstituted saturated monovalent organic group having 1 to 20 carbon atoms or an unsaturated monovalent organic group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms; R e1 is an organic group that generates one or more hydroxyl groups or carboxyl groups by the action of either or both of an acid and heat, as represented by the following general formula (e-4), and * represents a bond. [ka] (In the above general formula (e-4), R e3 is an organic group whose protecting group is removed by the action of either acid or heat, or both, and * is Y e )

[0097] (b) When the ligand-forming compound contains at least one crosslinking group represented by any one of the above (c-1) to (c-4), (d-1) to (d-4), and (e-1) to (e-3), sufficient thermal fluidity can be obtained during film formation. Therefore, when the ligand-forming compound is used in a metal-containing film-forming composition, a metal-containing film having excellent flatness can be formed.

[0098] From the viewpoint of productivity and stability of the metal-containing film-forming compound, the (b) ligand-forming compound is preferably a compound derived from a carboxy ligand, a compound derived from a β-diketone ligand, or a compound having a plurality of hydroxyl groups. These can be used alone or in combination of two or more.

[0099] An example of the compound derived from a carboxy ligand is a compound represented by the following formula (5). [ka] (In the above general formula (5), p is 0 or 1. When p is 1, X 1 is a divalent organic group having 2 to 20 carbon atoms, and W is an alkoxy group having 1 to 10 carbon atoms, or any one of the following general formula (5-A) and the above general formulas (d-1) to (d-4). 1 is a monovalent organic group having 8 to 30 carbon atoms, containing a crosslinking group having any of the structures represented by the above general formulas (c-2) to (c-4) and an aromatic ring. [ka] (In the above general formula (5-A), Y is a saturated divalent organic group having 1 to 20 carbon atoms or an unsaturated divalent organic group having 2 to 20 carbon atoms, and R A is any of the structures represented by the above general formulas (c-1) to (c-4), h represents 1 to 6, and * represents the bond to the carbon atom of the carbonyl.

[0100] A compound derived from a carboxy ligand having such a structure can improve the thermosetting properties of the metal-containing film-forming compound, and can form a metal-containing film that has excellent resistance to mixing with the resist top layer film.

[0101] In the above general formula (5), it is preferable that p is 1 and W is a structure represented by the following general formula (5-B). [ka] (In the above general formula (5-B), R A1is the structure represented by the above general formula (c-1), and R A2 is either of the structures represented by the above general formula (c-2) or (c-3), Z is either an oxygen atom or a secondary amine, and L 1 is a divalent hydrocarbon group having 1 to 10 carbon atoms, R A3 is a saturated monovalent organic group having 1 to 20 carbon atoms or an unsaturated monovalent organic group having 2 to 20 carbon atoms, t is 1 to 6, s is 0 to 5, t+s is 1 or more and 6 or less, r is 1 to 10, u is 0 or 1, m is 0 or 1, and * represents a bond to the carbon atom of the carbonyl.

[0102] Compounds derived from carboxy ligands having such structures improve the heat resistance of the metal-containing film-forming compound, so that the metal-containing film formed exhibits excellent film-forming properties and can also suppress the generation of sublimates during heat curing, thereby preventing contamination of the equipment.

[0103] In the general formula (5), p is 1, W is an alkoxy group having 1 to 10 carbon atoms, and X 1 is preferably any of the structures represented by the following general formula (5-C).

[0104] [ka] (In the formula, * represents a bond.)

[0105] Compounds derived from carboxy ligands having such structures improve the heat resistance of the metal-containing film-forming compound, so that the metal-containing film formed exhibits excellent film-forming properties and can also suppress the generation of sublimates during heat curing, thereby preventing contamination of the equipment.

[0106] Alternatively, in the general formula (5), p is 0, and X 1 is preferably any of the structures represented by the following general formula (5-D).

[0107] [ka] (In the above general formula (5-D), Rf is the same as Rc in the above general formula (c-2) or (c-3), and * represents the bond to the carbon atom of the carbonyl.

[0108] An example of the compound derived from a carboxy ligand is a compound represented by the following formula (6). [ka] (In the above general formula (6), X 2 is a divalent organic group having 1 to 31 carbon atoms, R 6A is any one of the above general formulas (e-1) to (e-3).

[0109] In the above general formula (6), X 2 is a divalent organic group having 1 to 31 carbon atoms, and from the viewpoint of thermosetting properties, is more preferably a saturated hydrocarbon having 1 to 20 carbon atoms or an unsaturated hydrocarbon having 2 to 20 carbon atoms.

[0110] In the above general formulas (e-1) to (e-3), Y e is a substituted or unsubstituted saturated divalent organic group having 1 to 20 carbon atoms or an unsaturated divalent organic group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms; Y e is preferably a saturated hydrocarbon having 1 to 20 carbon atoms or an unsaturated hydrocarbon having 2 to 20 carbon atoms.

[0111] In the general formulae (e-1) to (e-3), Y e If is a saturated hydrocarbon having 1 to 20 carbon atoms or an unsaturated hydrocarbon having 2 to 20 carbon atoms, the thermosetting property of the metal-containing film-forming compound can be further improved. This is also preferable from the viewpoint of raw material availability.

[0112] Y e Specific examples of the structure include, but are not limited to, the following structures. [ka] (*1 is the bond to the oxygen or nitrogen atom, *2 is Re1 )

[0113] In the above general formula (e-4), R e3 is a protecting group (an organic group from which a thermal acid labile group is eliminated) by the action of either or both of an acid and heat, and is preferably a tertiary hydrocarbyl group or a group that forms an acetal structure together with an adjacent oxygen atom, and is particularly preferably a tertiary hydrocarbyl group. The tertiary hydrocarbyl group is preferably one having 4 to 20 carbon atoms, and more preferably one having a smaller number of carbon atoms.

[0114] An example of a compound derived from a ligand derived from a β-diketone is a compound represented by the formula (7). [ka] (In the above general formula, R 7A ~R 7c is a monovalent organic group having 1 to 20 carbon atoms which may contain a hydrogen atom or a crosslinking group represented by any one of the above general formulas (c-1) to (c-4) and (d-1) to (d-4).

[0115] The compound of the general formula (7) preferably contains at least one crosslinking group represented by any one of the general formulae (c-1) to (c-4) and (d-1) to (d-4). Such a compound is preferable because it can further improve the thermosetting property of the compound for forming a metal-containing film.

[0116] Examples of compounds having a plurality of hydroxy groups include dihydric alcohols represented by any one of the formulas (7-A) to (7-C). [ka] (In the above general formula, R 7a ~R 7b is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a crosslinking group represented by any one of the above general formulas (c-1) to (c-4), R 7c ~R 7frepresents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a crosslinking group represented by any one of the following general formulas (c-1) to (c-4) and (d-1) to (d-4), and Y 2 is a divalent organic group having 1 to 10 carbon atoms. In the above general formula (7-A), adjacent R 7a and R 7b may be bonded to each other to form an unsaturated or saturated ring structure.

[0117] The compounds of the above general formulae (7-A) to (7-C) preferably contain at least one crosslinking group represented by any one of the above general formulae (c-1) to (c-4) and (d-1) to (d-4). Such compounds are preferred because they can further improve the thermosetting properties of the metal-containing film-forming compound.

[0118] In the metal-containing film-forming compound, the content of the polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms is preferably 10 mol% to 100 mol% of the total of the ligands coordinated to the metal atom, more preferably 20 mol% to 90 mol%, and even more preferably 25 mol% to 75 mol%. The content of the ligand derived from the (b) ligand-forming compound is preferably 0 mol% to 50 mol% of the total of the ligands coordinated to the metal atom, more preferably 0 mol% to 25 mol%. The content of the ligand other than the (b) ligand-forming compound, for example, the ligand derived from an alkoxy group having 1 to 10 carbon atoms, is preferably 0 mol% to 90 mol%, more preferably 0 mol% to 75 mol% of the total of the ligands coordinated to the metal atom.

[0119] [(c) Silicon-containing compound] Furthermore, during the synthesis reaction of the metal-containing film-forming compound, (c) a silicon-containing compound may be added in addition to the polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms.

[0120] (a) By substituting the hydrolyzable group of the metal-containing compound with a silicon-containing compound, the stability of the metal-containing film-forming compound in the metal-containing film-forming composition can be improved.

[0121] The silicon-containing compound may, for example, have a structure represented by the following general formula (4). [ka] (In the above general formula (4), R 3A , R 3B and R 3C is any organic group selected from an organic group having 1 to 30 carbon atoms and a bridging group having any of the structures represented by the following general formulas (b-1) to (b-3), a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and an aryl group having 1 to 20 carbon atoms. [ka] (In the above general formulas (b-1) to (b-3), R3 is hydrogen or a monovalent organic group having 1 to 10 carbon atoms, q is 0 or 1, and * is a bond.)

[0122] As the silicon-containing compound, any of the groups represented by the following formulas is more preferable, and trimethylsilanol is more preferable from the viewpoint of productivity. [ka] (In the above formula, * represents a bond to a metal atom.)

[0123] When the metal-containing film-forming compound contains a polydentate ligand having a cyclic ether structure having 2 to 13 carbon atoms and (c) a ligand derived from a silicon-containing compound, the content of the polydentate ligand having a cyclic ether structure having 2 to 13 carbon atoms in the metal-containing film-forming compound is preferably 10 mol% to 100 mol%, more preferably 20 mol% to 80 mol%, and even more preferably 25 mol% to 75 mol% of the total ligands coordinated to the metal atom. The content of the ligand derived from the silicon-containing compound (c) is preferably 10 mol% to 90 mol%, more preferably 20 mol% to 80 mol%, and even more preferably 25 mol% to 75 mol% of the total ligands coordinated to the metal atom. The content of the polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms and (c) a ligand other than a silicon-containing compound, for example a ligand derived from an alkoxy group having 1 to 10 carbon atoms, is preferably 0 mol % to 90 mol %, more preferably 0 mol % to 75 mol %, of the total ligands coordinated to the metal atom.

[0124] [Synthesis method] When synthesizing the compound for forming a metal-containing film of the present invention, as long as the compound for forming a metal-containing film contains a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms, the synthesis method is not particularly limited. For example, a metal alkoxide or metal acetylacetonate (acac) can be used for the (a) metal-containing compound, and the compound can be obtained by reacting an alkoxy or acac metal with a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms. After hydrolysis and condensation of the (a) metal-containing compound, the compound can be reacted with a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms, or after reaction of the (a) metal-containing compound with a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms, the compound can be hydrolyzed and condensed. When it is difficult to control the hydrolysis and condensation, the compound can be reacted with a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms in a non-water-containing environment. It is preferable to appropriately adjust these depending on the properties required for the compound for forming a metal-containing film and the metal-containing film. When (c) the silicon-containing compound has a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms as a ligand, it is preferable to react (a) the metal-containing compound with (c) the silicon-containing compound, and then react the resulting compound with the polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms.

[0125] As a method for carrying out a hydrolysis condensation reaction using (a) a metal-containing compound, for example, a method of carrying out a hydrolysis condensation reaction of (a) a metal-containing compound in a solvent containing water can be mentioned. In this case, other compounds having a hydrolyzable group may be added as necessary. In addition, an acid such as acetic acid may be added as a catalyst for the hydrolysis condensation reaction. The lower limit of the amount of water used in this hydrolysis condensation reaction is preferably 0.2 times by mole, more preferably 1 times by mole, and even more preferably 3 times by mole, relative to the hydrolyzable group of (a) a metal-containing compound or the like. The upper limit of the amount of water is preferably 20 times by mole, more preferably 15 times by mole, and even more preferably 10 times by mole.

[0126] The solvent used in the synthesis reaction of the metal-containing film-forming compound is not particularly limited, and for example, the same solvents as those exemplified as (B) organic solvents described later can be used. Typical solvents and solvent mixtures include ester, ether or alcohol functional groups, such as a 70 / 30 by volume mixture of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME). Examples of other solvents that can be used include butanediol monomethyl ether, ethylene glycol monomethyl ether, butanediol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, butanediol monopropyl ether, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, 1-butanol, 2-butanol, 2-methyl-1- Examples of the alkoxysilane include propanol, 4-methyl-2-ethanol, acetone, tetrahydrofuran, toluene, hexane, ethyl acetate, cyclohexanone, methyl amyl ketone, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, diamyl ether, isoamyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, t-butyl acetate, t-butyl propionate, propylene glycol mono t-butyl ether acetate, γ-butyrolactone, methyl isobutyl ketone, and cyclopentyl methyl ether.

[0127] <Metal-containing film forming composition> The present invention also provides a composition for forming a metal-containing film, the composition containing (A) the compound for forming a metal-containing film of the present invention, and (B) an organic solvent.

[0128] <(A) Metal-containing film-forming compound> The component (A) in the composition for forming a metal-containing film of the present invention is the above-mentioned compound for forming a metal-containing film of the present invention. The amount of the component (A) in the composition is not particularly limited, but may be, for example, 1 to 20 parts by mass, preferably 1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the total amount of the composition.

[0129] <(B) Organic solvent> The (B) organic solvent that can be used in the metal-containing film-forming composition of the present invention is not particularly limited as long as it dissolves the above-mentioned (A) metal-containing film-forming compound, and, if contained, the later-described (C) thermal acid generator, (D) photoacid generator, (E) crosslinking agent, (F) surfactant, and other additives.

[0130] Specifically, for example, the organic solvents described in paragraphs

[0091] to

[0092] of JP 2007-199653 A 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, γ-butyrolactone, or a mixture containing one or more of these is preferably used.

[0131] The amount of the organic solvent to be added is preferably 200 to 10,000 parts, and more preferably 250 to 5,000 parts, based on 100 parts by mass of the (A) compound for forming a metal-containing film.

[0132] <High boiling point solvent> In the metal-containing film-forming composition of the present invention, the (B) organic solvent may include a high-boiling organic solvent. The high-boiling organic solvent may be one or more organic solvents having a boiling point of 180° C. or higher.

[0133] For example, as the (B) organic solvent, 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 (high boiling point solvents) may be used.

[0134] The high boiling point solvent is not particularly limited as long as it can dissolve each component of the metal-containing film forming composition of the present invention, and may be any of hydrocarbons, alcohols, ketones, esters, ethers, chlorine-based solvents, etc., but 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, 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, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol-n-butyl ether, triethylene glycol 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, 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 of the diethyl ester include 6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, and dibutyl adipate. These may be used alone or in combination.

[0135] The high boiling point solvent may be appropriately selected from the above-mentioned solvents according to the temperature at which the metal-containing film-forming composition of the present invention is heat-treated. The boiling point of the high boiling point solvent is preferably 180°C to 300°C, more preferably 200°C to 300°C. If the solvent has such a boiling point, there is no risk of the solvent volatilizing too quickly during baking (heat treatment), so that the occurrence of defects due to drying during film formation can be suppressed. In addition, if the solvent has such a boiling point, the solvent does not volatilize and remains in the film after baking, so there is no risk of adversely affecting the film properties such as etching resistance.

[0136] When a high boiling point solvent is used, the blending amount is preferably 1 to 30 parts by mass per 100 parts by mass of an organic solvent having a boiling point of less than 180° C. Such a blending amount is preferable because it can impart sufficient thermal fluidity during baking and does not remain in the film, leading to deterioration of film properties such as etching resistance.

[0137] <Other ingredients> When the composition for forming a metal-containing film is a composition for forming a metal-containing film that can be used as a resist underlayer film used in a multilayer resist method, it is sufficient that the composition contains one or more of the above-mentioned (A) compound for forming a metal-containing film and (B) organic solvent, and may contain at least one or more of (C) a thermal acid generator, (D) a photoacid generator, (E) a crosslinking agent, and (F) a surfactant, as necessary.

[0138] Hereinafter, components that may be contained in the composition for forming a metal-containing film of the present invention other than the above (A) the compound for forming a metal-containing film and (B) the organic solvent will be described.

[0139] [(C) Thermal acid generator] In the metal-containing film-forming composition of the present invention, it is preferable to add a thermal acid generator (C) in order to promote the crosslinking reaction by heat.

[0140] Examples of the thermal acid generator (C) that can be used in the metal-containing film-forming composition of the present invention include those represented by the following general formula (7).

[0141] [ka] (In the formula, X A - R represents a non-nucleophilic counter ion. 70 , R 71 , R 72 , and R 73 each represents a hydrogen atom, or a linear, branched, or cyclic alkyl group, alkenyl group, oxoalkyl group, or oxoalkenyl group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group or aryloxoalkyl group having 7 to 12 carbon atoms, and some or all of the hydrogen atoms of these groups may be substituted with an alkoxy group or the like. 70 and R 71 , or R 70 , R 71 and R 72 may form a ring, and when a ring is formed, R 70 and R 71 , or R 70 , R 71 and R 72 represents an alkylene group having 3 to 10 carbon atoms, or a heteroaromatic ring having a nitrogen atom in the ring.

[0142] Above, R 70 , R 71 , R 72 , and R 73may be the same or different, and specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopropylmethyl group, a 4-methylcyclohexyl group, a cyclohexylmethyl group, a norbornyl group, and an adamantyl group.

[0143] Examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, a butenyl group, a hexenyl group, and a cyclohexenyl group.

[0144] Examples of the oxoalkyl group include a 2-oxocyclopentyl group, a 2-oxocyclohexyl group, a 2-oxopropyl group, a 2-cyclopentyl-2-oxoethyl group, a 2-cyclohexyl-2-oxoethyl group, and a 2-(4-methylcyclohexyl)-2-oxoethyl group.

[0145] Examples of the oxoalkenyl group include a 2-oxo-4-cyclohexenyl group and a 2-oxo-4-propenyl group.

[0146] Examples of the aryl group include a phenyl group, a naphthyl group, and the like; alkoxyphenyl groups such as a p-methoxyphenyl group, a m-methoxyphenyl group, an o-methoxyphenyl group, an ethoxyphenyl group, a p-tert-butoxyphenyl group, and a m-tert-butoxyphenyl group; alkylphenyl groups such as a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, an ethylphenyl group, a 4-tert-butylphenyl group, a 4-butylphenyl group, and a dimethylphenyl group; alkylnaphthyl groups such as a methylnaphthyl group and an ethylnaphthyl group; alkoxynaphthyl groups such as a methoxynaphthyl group and an ethoxynaphthyl group; dialkylnaphthyl groups such as a dimethylnaphthyl group and a diethylnaphthyl group; and dialkoxynaphthyl groups such as a dimethoxynaphthyl group and a diethoxynaphthyl group.

[0147] Examples of the aralkyl group include a benzyl group, a phenylethyl group, and a phenethyl group.

[0148] Examples of the aryloxoalkyl group include 2-aryl-2-oxoethyl groups such as a 2-phenyl-2-oxoethyl group, a 2-(1-naphthyl)-2-oxoethyl group, and a 2-(2-naphthyl)-2-oxoethyl group.

[0149] Also, R 70 and R 71 , or R 70 , R 71 and R 72When the nitrogen atom in the formula forms a heteroaromatic ring in the ring, imidazole derivatives (e.g., imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, etc.), pyrazole derivatives, furazan derivatives, pyrroline derivatives (e.g., pyrroline, 2-methyl-1-pyrroline, etc.), pyrrolidine derivatives (e.g., pyrrolidine, N-methylpyrrolidine, pyrrolidinone, N-methylpyrrolidone, etc.), imidazoline derivatives, imidazolidine derivatives, pyridine derivatives (e.g., pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 4-(1-butylpentyl)pyridine, dimethylpyridine, trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridine, Examples of the pyridine derivative include pyridine, 4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2-(1-ethylpropyl)pyridine, aminopyridine, dimethylaminopyridine, etc.), pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine derivatives, piperazine derivatives, morpholine derivatives, indole derivatives, isoindole derivatives, 1H-indazole derivatives, indoline derivatives, quinoline derivatives (e.g., quinoline, 3-quinolinecarbonitrile, etc.), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, phthalazine derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine derivatives, guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives, and the like.

[0150] Above, X A -Examples of the non-nucleophilic counter ion include halide ions such as chloride ion and bromide ion; fluoroalkyl sulfonates such as triflate, 1,1,1-trifluoroethanesulfonate, and nonafluorobutanesulfonate; aryl sulfonates such as tosylate, benzenesulfonate, 4-fluorobenzenesulfonate, and 1,2,3,4,5-pentafluorobenzenesulfonate; alkyl sulfonates such as mesylate and butanesulfonate; imide acids such as bis(trifluoromethylsulfonyl)imide, bis(perfluoroethylsulfonyl)imide, and bis(perfluorobutylsulfonyl)imide; methide acids such as tris(trifluoromethylsulfonyl)methide and tris(perfluoroethylsulfonyl)methide; and sulfonates substituted with fluoro at the α-position as shown in the following general formula (8) and sulfonates substituted with fluoro at the α- and β-positions as shown in the following general formula (9).

[0151] [ka]

[0152] In the above general formula (8), R 81 is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 23 carbon atoms, an acyl group, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aryloxy group. 91 is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0153] Specific examples of the thermal acid generator include, but are not limited to, the following.

[0154] [ka]

[0155] The (C) thermal acid generator contained in the metal-containing film-forming composition of the present invention may be used alone or in combination of two or more. The amount of the thermal acid generator added is preferably 0.05 to 30 parts, more preferably 0.1 to 10 parts, based on 100 parts of the (A) compound for forming a metal-containing film. If it is 0.05 parts or more, the amount of acid generated and the crosslinking reaction are sufficient, and if it is 30 parts or less, there is little risk of a mixing phenomenon occurring due to the acid migrating to the upper resist layer.

[0156] [(D) Photoacid generator] The metal-containing film-forming composition of the present invention may contain a photoacid generator (D) in order to appropriately adjust the pattern shape of the resist upper layer film, exposure sensitivity, etc. The photoacid generator may be used alone or in combination of two or more.

[0157] As the photoacid generator, for example, those described in paragraphs

[0160] to

[0179] of JP 2009-126940 A can be used. The amount of the photoacid generator added is preferably 0.05 to 30 parts, more preferably 0.1 to 10 parts, based on 100 parts of the (A) metal-containing film-forming compound. If the amount of the photoacid generator added is within the above range, the resolution is good, and there is no risk of problems with foreign matter occurring after resist development or during peeling.

[0158] [(E) Crosslinking agent] In addition, a crosslinking agent (E) may be added to the metal-containing film-forming composition of the present invention in order to enhance curability and further suppress intermixing with the resist upper layer film.

[0159] The crosslinking agent is not particularly limited, and various known crosslinking agents can be widely used. Examples include melamine-based crosslinking agents, glycoluril-based crosslinking agents, benzoguanamine-based crosslinking agents, urea-based crosslinking agents, β-hydroxyalkylamide-based crosslinking agents, isocyanurate-based crosslinking agents, aziridine-based crosslinking agents, oxazoline-based crosslinking agents, epoxy-based crosslinking agents, and phenol-based crosslinking agents. The (E) crosslinking agent can be used alone or in combination of two or more. When the crosslinking agent is added, the amount added is preferably 5 to 50 parts, more preferably 10 to 40 parts, relative to 100 parts of the (A) metal-containing film-forming compound. If the amount added is 5 parts or more, sufficient curability is exhibited, and intermixing with the resist upper layer film can be suppressed. On the other hand, if the amount added is 50 parts or less, there is no risk of deterioration of dry etching resistance due to a decrease in the ratio of the (A) metal-containing film-forming compound in the composition.

[0160] Specific examples of the melamine-based crosslinking agent include hexamethoxymethylated melamine, hexabutoxymethylated melamine, alkoxy- and / or hydroxy-substituted products thereof, and partial self-condensates thereof.

[0161] Specific examples of glycoluril crosslinking agents include tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril, alkoxy and / or hydroxy substituted products thereof, and partial self-condensates thereof.

[0162] Specific examples of benzoguanamine-based crosslinking agents include tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, alkoxy- and / or hydroxy-substituted products thereof, and partial self-condensates thereof.

[0163] Specific examples of the urea-based crosslinking agent include dimethoxymethylated dimethoxyethyleneurea, its alkoxy and / or hydroxyl substituted derivatives, and partial self-condensates thereof.

[0164] A specific example of the β-hydroxyalkylamide crosslinking agent is N,N,N',N'-tetra(2-hydroxyethyl)adipamide.

[0165] Specific examples of the isocyanurate crosslinking agent include triglycidyl isocyanurate and triallyl isocyanurate.

[0166] Specific examples of the aziridine crosslinking agent include 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate].

[0167] Specific examples of the oxazoline crosslinking agent include 2,2'-isopropylidenebis(4-benzyl-2-oxazoline), 2,2'-isopropylidenebis(4-phenyl-2-oxazoline), 2,2'-isopropylidenebis(4-phenyl-2-oxazoline), 2,2'-methylenebis4,5-diphenyl-2-oxazoline, 2,2'-methylenebis-4-phenyl-2-oxazoline, 2,2'-methylenebis-4-tertbutyl-2-oxazoline, 2,2'-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylenebis(2-oxazoline), and 2-isopropenyloxazoline copolymer.

[0168] Specific examples of epoxy crosslinking agents include diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, poly(glycidyl methacrylate), trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, and pentaerythritol tetraglycidyl ether.

[0169] A specific example of the phenol-based crosslinking agent is a compound represented by the following general formula (10). [ka] (In the formula, Q is a single bond or a q 1 R is a 4-valent hydrocarbon group. 16 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. 1 is an integer between 1 and 5.)

[0170] Q is a single bond or a carbon number of 1 to 20 1 It is a q-valent hydrocarbon group. 1 is an integer of 1 to 5, and more preferably 2 or 3. Specific examples of Q include methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylisopropylbenzene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, and eicosane. 16 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Specific examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, an isopentyl group, a hexyl group, an octyl group, an ethylhexyl group, a decyl group, and an eicosanyl group, and a hydrogen atom or a methyl group is preferable.

[0171] Specific examples of the compound represented by the above general formula (10) include the following compounds. Among these, from the viewpoint of improving the curability and thickness uniformity of the adhesive film, hexamethoxymethylated products of triphenolmethane, triphenolethane, 1,1,1-tris(4-hydroxyphenyl)ethane, and tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene are preferred.

[0172] [ka]

[0173] [ka] (In the formula, R 16 is as above.)

[0174] [(F) Surfactant] To the metal-containing film-forming composition of the present invention, a surfactant (F) can be added in order to improve the coating property in spin coating. The surfactant can be used alone or in combination of two or more.

[0175] As the surfactant, for example, those described in paragraphs

[0142] to

[0147] of JP 2009-269953 A can be used. The amount of the surfactant added is preferably 0.001 to 20 parts, more preferably 0.01 to 10 parts, per 100 parts of the (A) metal-containing film-forming compound. Within this range, the coating property is reliably improved, and a thin and uniform adhesive film can be formed.

[0176] [Plasticizer] A plasticizer can be added to the metal-containing film-forming composition of the present invention. The plasticizer is not particularly limited, and various known plasticizers can be widely used. Examples include low molecular weight compounds such as phthalates, adipic esters, phosphates, trimellitates, and citrates, and polymers such as polyethers, polyesters, and polyacetal polymers described in JP-A-2013-253227. The amount of plasticizer added is preferably 1% by mass to 500% by mass with respect to 100 parts of the (A) metal-containing film-forming compound. When the amount added is within such a range, the pattern filling and averaging are excellent.

[0177] <Metal-containing film formation method> In the present invention, the above-mentioned composition for forming a metal-containing film can be used to form a metal-containing film as a resist underlayer film of a multi-layer resist film used in lithography, for example.

[0178] In the method for forming a resist underlayer film using the composition for forming a metal-containing film of the present invention, the composition for forming a metal-containing film is coated on a substrate to be processed by spin coating or the like. After spin coating, the solvent is evaporated, and baking (heat treatment) is performed to promote a crosslinking reaction and prevent mixing with the resist upper layer film. Baking is preferably performed at 100°C or higher and 450°C or lower for 10 to 600 seconds, more preferably 200°C or higher and 300°C or lower for 10 to 300 seconds. Considering the influence on device damage and wafer deformation, the upper limit of the heating temperature in the wafer process of lithography is preferably 450°C or lower, more preferably 300°C or lower.

[0179] In addition, in a method for forming a resist underlayer film using the composition for forming a metal-containing film of the present invention, the composition for forming a metal-containing film of the present invention can be coated on a substrate to be processed by a spin coating method or the like as described above, and the composition for forming a metal-containing film can be baked and cured in an atmosphere having an oxygen concentration of 0.1 vol.% or more and 21 vol.% or less to form a metal-containing film.

[0180] By baking the metal-containing film-forming composition of the present invention in such an oxygen atmosphere, a sufficiently cured film can be obtained. Although the atmosphere during baking may be air, it is preferable to seal in an inert gas such as N2, Ar, or He to reduce oxygen in order to prevent oxidation of the metal-containing film. In order to prevent oxidation, it is necessary to control the oxygen concentration, which is preferably 1000 ppm or less, more preferably 100 ppm or less (volume basis). Preventing oxidation of the metal-containing film during baking is preferable because it does not increase absorption or reduce etching resistance.

[0181] Alternatively, the above-mentioned metal-containing film-forming composition can be used to form a metal-containing film as an intermediate film of a multi-layer resist film used in lithography, for example.

[0182] <Pattern formation method using the composition for forming a metal-containing film> In addition, the present invention provides a method for forming a pattern by a two-layer resist process using the metal-containing film-forming composition of the present invention, which is a method for forming a pattern on a substrate to be processed, comprising the steps of: (I-1) a step of applying the composition for forming a metal-containing film of the present invention onto a substrate to be processed, followed by heat treatment to form a metal-containing film; (I-2) forming a resist top layer film on the metal-containing film using a photoresist material; (I-3) a step of forming a pattern on the resist upper layer film by pattern-exposing the resist upper layer film and then developing the resist upper layer film with a developer; (I-4) a step of transferring the pattern to the metal-containing film by dry etching using the resist top layer film on which the pattern is formed as a mask; and (I-5) A step of processing the substrate to be processed using the metal-containing film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. The present invention provides a pattern forming method comprising the steps of:

[0183] The resist top layer film of the two-layer resist process exhibits etching resistance by chlorine-based gas, so in the two-layer resist process, the dry etching of the metal-containing film is preferably performed by using the resist top layer film as a mask with an etching gas mainly made of chlorine-based gas.The metal-containing film exhibits etching resistance by fluorine-based gas, so the dry etching of the substrate to be processed is preferably performed by using the metal-containing film as a mask with an etching gas mainly made of fluorine-based gas.

[0184] In addition, the present invention provides a method for forming a pattern by a three-layer resist process using the metal-containing film-forming composition of the present invention, which is a method for forming a pattern on a substrate to be processed, comprising the steps of: (II-1) forming a resist underlayer film on a substrate to be processed; (II-2) a step of applying a composition for forming a metal-containing film of the present invention onto the resist underlayer film, followed by heat treatment to form a metal-containing film; (II-3) forming a resist top layer film on the metal-containing film using a photoresist material; (II-4) a step of forming a pattern on the resist upper layer film by pattern-exposing the resist upper layer film and then developing the resist upper layer film with a developer; (II-5) a step of transferring the pattern to the metal-containing film by dry etching using the resist upper layer film on which the pattern is formed as a mask; (II-6) a step of transferring a pattern to the resist underlayer film by dry etching using the metal-containing film to which the pattern has been transferred as a mask; (II-7) a step of processing the substrate using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate; The present invention provides a pattern forming method comprising the steps of:

[0185] The metal-containing film formed by the metal-containing film-forming composition of the present invention and used as the intermediate film in the above three-layer resist process exhibits etching resistance by oxygen-based gas, so in the above three-layer resist process, the dry etching of the organic resist underlayer film using the metal-containing film as a mask is preferably performed using an etching gas mainly composed of oxygen-based gas.The organic underlayer film exhibits etching resistance by fluorine-based gas, so the dry etching of the substrate to be processed using the organic underlayer film as a mask is preferably performed using an etching gas mainly composed of fluorine.

[0186] In the above pattern forming method, the resist upper layer film may be either positive or negative, and the same photoresist composition as that usually used can be used. When the resist upper layer film is formed from the above photoresist composition, a spin coating method is preferred.

[0187] When forming a resist upper layer film using a photoresist composition by spin coating, pre-baking is performed after resist coating, preferably at 60 to 180° C. for 10 to 300 seconds. Thereafter, exposure is performed according to a conventional method, post-exposure baking (PEB) and development are performed to obtain a resist pattern. The thickness of the resist upper layer film is not particularly limited, but is preferably 10 to 500 nm, particularly preferably 20 to 400 nm.

[0188] Examples of the exposure light include high-energy rays with a wavelength of 300 nm or less, specifically far ultraviolet rays, KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F2 laser light (157 nm), Kr2 laser light (146 nm), Ar2 laser light (126 nm), soft X-rays (EUV) of 3 to 20 nm, electron beams (EB), ion beams, X-rays, and the like.

[0189] The method for forming the pattern on the resist upper layer film is preferably photolithography with a wavelength of 5 nm or more and 300 nm or less, direct drawing with an electron beam, nanoimprinting, or a combination of these.

[0190] In the pattern forming method, the development method is preferably alkaline development or development using an organic solvent.

[0191] Next, etching is performed using the obtained resist pattern as a mask. For example, etching of a metal-containing film in a two-layer resist process is performed using a chlorine-based gas and the upper layer resist pattern as a mask. This forms a metal-containing film pattern. Next, etching of a substrate to be processed is performed using the obtained metal-containing film pattern as a mask. Etching of the workpiece can be performed by a conventional method. For example, if the workpiece is a SiO2, SiN, or silica-based low dielectric constant insulating film, etching is performed mainly using a fluorocarbon-based gas.

[0192] The metal-containing film obtained by using the metal-containing film-forming composition of the present invention is characterized by excellent etching resistance when etching the workpiece.

[0193] Examples of organic resist underlayer film materials that can be used for the resist underlayer film include those already known as underlayer films for a three-layer resist method or a two-layer resist method using a silicon resist composition. For example, JP-A-2012-1687, JP-A-2012-77295, JP-A-2004-264710, JP-A-2005-043471, JP-A-2005-250434, JP-A-2007-293294, JP-A-2008-65303, JP-A-2004-205 685, JP 2007-171895 A, JP 2009-14816 A, JP 2007-199653 A, JP 2008-274250 A, JP 2010-122656 A, JP 2012-214720 A, JP 2014-29435 A, International Publication WO Examples of resins and compositions disclosed in JP-A-2012 / 077640, WO2010 / 147155, WO2012 / 077640, WO2010 / 147155, WO2012 / 176767, JP-A-2005-128509, JP-A-2006-259249, JP-A-2006-259482, JP-A-2006-293298, JP-A-2007-316282, JP-A-2012-145897, JP-A-2017-119671, JP-A-2019-44022, and the like can be mentioned.

[0194] The resist underlayer film can be formed on a substrate to be processed by, for example, a composition solution containing the organic resist underlayer film material, by spin coating or the like, in the same manner as the photoresist composition. After forming the organic resist underlayer film by spin coating or the like, it is desirable to bake the film to evaporate the organic solvent. The baking temperature is preferably in the range of 100 to 600°C, and the baking time is preferably in the range of 10 to 300 seconds.

[0195] Instead of the organic resist underlayer film material, an organic hard mask formed by a CVD method or an ALD method can also be used.

[0196] In the case of a three-layer resist process, the dry etching of the metal-containing film is performed, for example, by using a chlorine-based gas with the upper layer resist pattern as a mask. This forms a metal-containing film pattern. Next, the resist underlayer film is etched with an oxygen-based gas with the obtained metal-containing film pattern as a mask. This forms a resist underlayer film pattern. Next, the substrate to be processed is etched with the obtained organic resist underlayer film pattern as a mask.

[0197] The metal-containing film obtained by using the metal-containing film-forming composition of the present invention is characterized by excellent etching resistance during etching of these resist underlayer films.

[0198] The workpiece (substrate) is not particularly limited, and may be a substrate such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, or Al, or a substrate on which a workpiece layer is formed. As the workpiece layer, various low-k films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, or Al-Si and their stopper films are used, and may be formed to a thickness of usually 50 to 10,000 nm, particularly 100 to 5,000 nm. When forming a workpiece layer, the substrate and the workpiece layer are made of different materials.

[0199] Here, an example of a pattern forming method by the above three-layer resist process will be described with reference to FIG. 1. In this example, first, as shown in FIG. 1(A), an organic resist underlayer film 3 is formed on a processable layer 2 of a processable substrate 10 consisting of a substrate 1 and a processable layer 2 thereon, using an organic resist underlayer film material, a metal-containing film 4 is formed on the organic resist underlayer film 3 using a metal-containing film forming composition of the present invention, and a resist upper layer film 5 is formed on the metal-containing film 4 using a photoresist material. Subsequently, as shown in FIG. 1(B), the exposed portion 6 of the resist upper layer film is exposed to light in a pattern. Next, as shown in FIG. 1(C), the resist upper layer film is developed with a developer to form a resist upper layer film pattern 5a on the resist upper layer film. Next, as shown in FIG. 1(D), the resist upper layer film on which the pattern 5a is formed is used as a mask to transfer the pattern to the metal-containing film 4 by dry etching, thereby obtaining a metal-containing film pattern 4a. Next, as shown in Fig. 1(E), the metal-containing film onto which the pattern 4a has been transferred is used as a mask to transfer the pattern to the organic resist underlayer film by dry etching to obtain an organic resist underlayer film pattern 3a. Then, as shown in Fig. 1(F), the processable layer 2 on the substrate 1 is processed using the organic resist underlayer film onto which the pattern 3a has been formed as a mask to form a pattern 2a on the substrate 10 to be processed.

[0200] In addition, an example of a pattern forming method by the two-layer resist process will be described with reference to FIG. 2. In this example, first, as shown in FIG. 2(G), a metal-containing film 4 is formed on the workpiece layer 2 of a workpiece substrate 10 consisting of a substrate 1 and a workpiece layer 2 thereon using the metal-containing film forming composition of the present invention, and a resist upper layer film 5 is formed on the metal-containing film 4 using a photoresist material. Then, as shown in FIG. 2(H), the exposed portion 6 of the resist upper layer film is exposed to light in a pattern. Next, as shown in FIG. 2(I), the resist upper layer film is developed with a developer to form a resist upper layer film pattern 5a on the resist upper layer film. Next, as shown in FIG. 2(J), the resist upper layer film on which the pattern 5a is formed is used as a mask to transfer the pattern to the metal-containing film 4 by dry etching to obtain a metal-containing film pattern 4a. Then, as shown in FIG. 2(K), the workpiece layer 2 on the substrate 1 is processed using the metal-containing film on which the pattern 4a is formed as a mask to form a pattern 2a on the workpiece substrate 10. EXAMPLES

[0201] The present invention will be explained in more detail below by showing Synthesis Examples, Comparative Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to these.

[0202] [(A) Synthesis example of compound for forming metal-containing film] In the following synthesis examples, the following organic group raw material group G: (G1) to (G15) and the silicon-containing organic group raw material group H: (H1) to (H2) were used.

[0203] Raw material group G: (G1) to (G15) and raw material group H: (H1) to (H2) are shown below.

[0204] [ka]

[0205] [ka]

[0206] As the metal source M, the following metal compounds were used. (M1): Titanium tetraisopropoxide (Sigma-Aldrich Corp, 377996) (M2): Hf(OBu)4: Hafnium(IV) n-butoxide (Sigma-Aldrich Corp, 667943) (M3): Zr(OBu)4: Zirconium(IV) tetrabutoxide (80% by mass solution in 1-butanol) (Tokyo Chemical Industry Co., Ltd., Z0016)

[0207] [Synthesis Example 1] Synthesis of metal-containing film-forming compound (A-1) Under a nitrogen atmosphere, 28.4 g of titanium tetraisopropoxide (M1) was dissolved in 50.0 g of 2-propanol, and while stirring, a solution of 2.7 g of deionized water and 50.0 g of IPA was added dropwise at room temperature over 2 hours. 15.8 g of organic group raw material group (G1) was added to the obtained solution and stirred at room temperature for 30 minutes. After concentrating this solution at 30°C under reduced pressure, it was further heated to 60°C and continued to be heated under reduced pressure until no distillate was produced. When no distillate was observed, 120.0 g of PGMEA / PGME (weight ratio 70 / 30) solution was added and heated at 40°C under reduced pressure until no IPA was produced, to obtain a PGMEA / PGME solution of metal-containing film-forming compound (A-1).

[0208] [Synthesis of compounds (A-2) to (A-3)] Compounds (A-2) to (A-3) shown in Table 1 were obtained under the same reaction conditions as in Synthesis Example 1, except that the metal source M and compound group G were used in the amounts shown in Table 1.

[0209] [Table 1]

[0210] [Synthesis Example 2] Synthesis of metal-containing film-forming compound (A-4) Under a nitrogen atmosphere, 47.9 g of zirconium (IV) tetrabutoxide (M3) was dissolved in 65.9 g of PGMEA / PGME (weight ratio 70 / 30) solution, the reaction temperature was increased to 60 ° C. while stirring, and a mixture of 18.6 g of compound G4 suspended in 27.5 g of PGMEA / PGME (weight ratio 70 / 30) solution was added to the reaction system, and stirring was continued for 1 hour while keeping the reaction temperature at 60 ° C. After cooling to room temperature, the resulting reaction solution was filtered with a 0.45 μm PTFE filter to obtain a PGMEA / PGME solution of the metal-containing film-forming compound (A-4).

[0211] [Synthesis of compounds (A-5) to (A-11)] Compounds (A-5) to (A-11) shown in Table 2 were obtained under the same reaction conditions as in Synthesis Example 2, except that the metal source M and compound group G were used in the amounts shown in Table 2.

[0212] [Table 2]

[0213] [Synthesis Example 3] Synthesis of metal-containing film-forming compound (A-12) Under a nitrogen atmosphere, 12.0 g of zirconium (IV) tetrabutoxide (M3) was dissolved in 16.5 g of PGMEA / PGME (weight ratio 70 / 30) solution, and the reaction temperature was increased to 50° C. while stirring, and 6.8 g of compound H1 was dropped into the solution. After the dropwise addition, the reaction temperature was set to 60° C. and stirring was continued for 2 hours. Next, a mixture obtained by suspending 5.0 g of compound G3 in 6.8 g of PGMEA / PGME (weight ratio 70 / 30) solution was added to the reaction system, and stirring was continued for 1 hour while keeping the reaction temperature at 60° C. After cooling to room temperature, the resulting reaction solution was filtered through a 0.45 μm PTFE filter to obtain a PGMEA / PGME solution of the metal-containing film-forming compound (A-12).

[0214] [Synthesis of compounds (A-13) to (A-14) and comparative compounds (R-1) to (R-4)] Compounds (A-13) to (A-14) and comparative compounds (R-1) to (R-4) shown in Table 3 were obtained under the same reaction conditions as in Synthesis Example 3, except that the metal source M, compound group G, and compound group H were used in the amounts shown in Table 3.

[0215] [Table 3]

[0216] Preparation of metal-containing film-forming compositions (MUL-1 to 19, comparative MUL-1 to 4) The metal-containing film-forming compositions were prepared using the above-mentioned metal-containing film-forming compounds (A-1) to (A-14), the thermal acid generator (AG1), the photoacid generator (AG2), the crosslinking agents (XL1) to (XL2), and the high boiling point solvent (F1: ethylene glycol dibenzyl ether: boiling point 364° C.). After dissolving in an organic solvent in the ratio shown in Table 4, the metal-containing film-forming compositions (MUL-1 to 19, comparative MUL-1 to 4) were each prepared by filtering through a 0.1 μm fluororesin filter.

[0217] [ka]

[0218] [Table 4]

[0219] [Example 1: Contact angle evaluation] The metal-containing film-forming compositions (MUL-1 to 19, Comparative Examples MUL-1 to 4) prepared above were applied onto silicon substrates and baked at 250°C for 60 seconds to produce metal-containing films with a thickness of 45 nm. The contact angle (CA1) of each cured film with pure water was measured. The results are shown in Table 5 below.

[0220] [Table 5]

[0221] As shown in Table 5, all of the metal-containing film-forming compositions (MUL-1 to 19) of the present invention having a cyclic ether structure formed films with a contact angle of more than 60° with respect to pure water, and good adhesion to the resist pattern can be expected. In particular, the contact angle was found to be high for the metal-containing film-forming compositions using compounds having an epoxy or oxetane structure. In addition, the contact angle was found to be high for Examples 1-15 and 1-17 to 1-18, which used compositions containing a thermal acid generator (AG1). Although the effect is unclear, it is presumed that this is due to the action of the acid generator promoting curing due to the ring-opening reaction of the epoxy or oxetane structure. On the other hand, the comparative metal-containing film-forming compositions not having a cyclic ether structure (Comparative Examples MUL-1 to MUL-4) showed low contact angles, and therefore it is expected that the adhesion to the resist pattern is insufficient.

[0222] [Example 2: Evaluation of optical constants (n / k)] The metal-containing film-forming compositions (MUL-2 to 19, and comparative examples MUL-1 to 4) were applied onto a silicon substrate and baked at 250°C for 60 seconds. The optical constants (refractive index n, extinction coefficient k) at a wavelength of 193 nm were then determined using a variable angle of incidence spectroscopic ellipsometer (VASE) manufactured by JA Woollam Co. The results are also shown in Table 6.

[0223] [Table 6]

[0224] As shown in Table 6, the compositions for forming metal-containing films (MUL-2 to 19) of the present invention containing hafnium and zirconium all had n values ​​of 1.8 or more and k values ​​between 0.1 and 0.5. The optical constants depend on the film thickness, the type of the upper layer film, etc., but generally, if the n value is between 1.8 and 2.3 and the k value is between 0.1 and 0.5, even if the metal-containing film is formed as a thin film of 20 nm or less, the reflected light from the substrate in ArF immersion and high NA exposure can be suppressed to a considerable extent, and it is applicable as an underlayer film for photoresist patterning. In the above examples, the optical constants are all in a suitable range, and it is found that it is applicable to photoresist patterning as a resist underlayer film. On the other hand, in Comparative Examples 2-3 and 2-4, the n value is 1.8 or less, probably because there are many organic components in the metal-containing film, and it is expected that the suppression performance of the substrate reflected light in ArF immersion and high NA exposure is insufficient.

[0225] [Example 3: Etching resistance evaluation] The metal-containing film-forming compositions (MUL-1 to 19 and Comparative Examples MUL-1 to 4) were applied onto a silicon substrate and heated at 250°C for 60 seconds using a hot plate to form a metal-containing film having a thickness of 50 nm (film thickness a). In Comparative Examples 3 to 5, the following silicon-containing resist intermediate film material (SOG-1) was applied and baked at 220°C for 60 seconds to form a resist intermediate film having a thickness of 50 nm.

[0226] Silicon-containing resist intermediate film material (SOG-1) was prepared by dissolving a polymer represented by ArF silicon-containing intermediate film polymer (SiP1) and a thermal crosslinking catalyst (CAT1) in a solvent containing 0.1 mass % of FC-4430 (manufactured by Sumitomo 3M) in the ratios shown in Table 7, and filtering the solution through a fluorine resin filter having a pore size of 0.1 μm.

[0227] [Table 7]

[0228] The structural formulae of the ArF silicon-containing intermediate film polymer (SiP1) and thermal crosslinking catalyst (CAT1) used are shown below. [ka]

[0229] In Comparative Example 3-6, the following organic resist underlayer film material (SOC-1) was applied and baked at 350° C. for 60 seconds to form a resist underlayer film with a thickness of 50 nm.

[0230] As the organic resist underlayer film material (SOC-1), a polymer represented by organic underlayer film polymer (CP1) was dissolved in a solvent containing 0.1 mass % of FC-4430 (manufactured by Sumitomo 3M Limited) in the ratio shown in Table 8, and the resultant was filtered through a fluorine resin filter having a pore size of 0.1 μm to prepare an organic resist underlayer film material (SOC-1).

[0231] [Table 8]

[0232] The structural formula of the organic underlayer polymer (CP1) used is shown below. [ka] Mw=7,000, Mw / Mn=3.50

[0233] Next, etching was performed using CF4 gas and O2 gas under the following conditions using a ULVAC etching system CE-300I, and the film thickness b was measured. The film thickness etched in one minute using each gas was calculated as the etching rate (nm / min) from the film thickness etched in the specified time using each gas (film thickness b - film thickness a).

[0234] The etching rate for CF4 gas was judged as "A (very good)" when it was 20 nm / min or less, "B (good)" when it was 20 nm / min to 30 nm / min, and "C (poor)" when it was 30 nm / min or more. The results are shown in Table 9.

[0235] The etching rate for O2 gas was judged as "A (very good)" when it was 20 nm / min or less, "B (good)" when it was 20 nm / min to 30 nm / min, and "C (poor)" when it was 30 nm / min or more. The results are shown in Table 9.

[0236] Dry etching conditions with CF4 gas Pressure: 3Pa Antenna RF power: 100W Bias RF power: 15W CF4 gas flow rate: 15sccm Time: 30sec

[0237] Dry etching conditions with O2 gas Pressure: 3Pa Antenna RF power: 300W Bias RF power: 10W O2 gas flow rate: 25sccm Time: 30sec

[0238] [Table 9]

[0239] As shown in Table 9, it was found that all of the metal-containing film-forming compositions (MUL-1 to 19) of the present invention exhibit excellent etching resistance to CF4 gas and O2 gas. Since they have excellent resistance to etching using O2 gas compared to SOG-1 used in Comparative Example 3-5, they can be said to be suitable for a three-layer resist process in which a resist pattern is transferred to a substrate to be processed in combination with an organic resist underlayer film. Since they have excellent etching resistance to CF4 gas compared to SOC-1 used in Comparative Example 3-6, they can be said to be suitable for a two-layer resist process in which a resist pattern is transferred to a substrate to be processed in combination with a photoresist upper layer film.

[0240] [Example 4: Pattern formation method] The above SOC-1 was used as an organic underlayer film on a substrate, and the film was applied by spin coating on a Si wafer and baked at 350°C for 60 seconds to produce a carbon film with a thickness of 60 nm. The carbon ratio of the carbon film was 46 atomic%, and the optical constant (n / k) at a wavelength of 193 nm was 1.42 / 0.50. A composition obtained by diluting the metal-containing film-forming composition (MDL-3 to 19, and Comparative Examples MDL-1 to 4) with an organic solvent (PGMEA / PGME = 700 / 300 parts by mass) was applied thereon, and heated at 250°C for 60 seconds using a hot plate to form a resist intermediate film with a thickness of 15 nm. A single layer resist for ArF, which is a resist upper layer film material, was applied thereon, and baked at 105°C for 60 seconds to form a photoresist film with a thickness of 100 nm. An immersion protective film material (TC-1) was applied onto the photoresist film and baked at 90° C. for 60 seconds to form a protective film with a thickness of 50 nm.

[0241] The resist top layer film material (ArF single layer resist) was prepared by dissolving a polymer (RP1), an acid generator (PAG1), and a basic compound (Amine1) in a solvent containing 0.1 mass % of a surfactant FC-4430 (Sumitomo 3M Limited) in the ratios shown in Table 10, and filtering the solution through a 0.1 μm fluorine resin filter.

[0242] [Table 10]

[0243] The polymer (RP1), acid generator (PAG1), and basic compound (Amine1) used in the resist top layer material (ArF single layer resist) are shown below. [ka]

[0244] The immersion protective film material (TC-1) was prepared by dissolving the protective film polymer (PP1) in an organic solvent in the ratio shown in Table 11, and filtering through a 0.1 μm fluorine resin filter.

[0245] [Table 11]

[0246] The protective film polymer (PP1) used in the immersion protective film material (TC-1) is shown below. [ka]

[0247] Next, the film was exposed using an ArF immersion exposure tool (Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.78, 35 degree dipole s-polarized illumination, 6% halftone phase shift mask), baked at 100°C for 60 seconds (PEB), and developed in a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to obtain a 50 nm 1:1 positive line and space pattern (resist upper layer film pattern).

[0248] The reflectance was calculated using PROLITH 2020a (LithoTech Japan Co., Ltd.). The film thickness of the metal-containing film was fixed at 10 nm, and the reflectance was calculated when n of the metal-containing film was 1.60 to 2.20 and k was 0.15 to 0.50. The optical constant (n / k) is preferably such that the reflected light from the underlying substrate during pattern exposure can be reduced to 1.0% or less. The cross section of the pattern was observed using an S-4700 (electron microscope manufactured by Hitachi, Ltd.). The results are shown in Table 12.

[0249] Next, the resist intermediate film was etched by dry etching using the resist upper layer film pattern as a mask to form a hard mask pattern, the organic lower layer film was etched using the obtained hard mask pattern as a mask to form a pattern, and the SiO2 film was etched using the obtained resist lower layer film pattern as a mask. The etching conditions are as shown below.

[0250] The cross section of the pattern was observed with an S-4700 (electron microscope manufactured by Hitachi, Ltd.) The results are shown in Table 12.

[0251] Conditions for transferring the hard mask pattern to the metal-containing film (resist intermediate film). Dry etching conditions with Cl2 gas Pressure: 1Pa Antenna RF power: 320W Bias RF power: 30W Cl2 gas flow rate: 25sccm Time: 15sec

[0252] Transfer conditions of the resist intermediate film pattern to the organic underlayer film. Dry etching conditions with O2 gas Pressure: 1Pa Antenna RF power: 300W Bias RF power: 10W O2 gas flow rate: 25sccm Time: 20sec

[0253] Transfer conditions of resist underlayer film pattern onto SiO2 film. Dry etching conditions with CF4 gas Pressure: 1Pa Antenna RF power: 100W Bias RF power: 15W CF4 gas flow rate: 15sccm Time: 60sec

[0254] [Table 12]

[0255] As shown in Table 12, it was confirmed that the metal-containing film-forming compositions of the present invention (MUL-3 to 19) all had good pattern shapes after development. It is presumed that the metal-containing film material of the present invention contains a cyclic ether structure, and therefore has high adhesion to the resist pattern and optical constants that can sufficiently reduce the substrate reflected light during pattern exposure, and therefore a good resist pattern was obtained. In addition, after etching after substrate transfer, the resist upper layer film pattern was finally transferred well to the substrate, and it was confirmed that the composition is suitable for use in microfabrication by the multilayer resist method. In contrast, the metal-containing film-forming compositions (Comparative Examples MUL-1 to 4) that had low contact angles in the contact angle evaluation of Example 1 showed collapse of the resist upper layer film pattern after development.

[0256] From the above, the compound for forming a metal-containing film, the composition using the compound, and the pattern formation method of the present invention have high adhesion to a resist upper layer film pattern, have an effect of suppressing collapse of a fine pattern, and give a pattern shape of the resist upper layer film with high rectangularity, and therefore are particularly suitable for use in a multilayer resist process and are extremely useful in fine patterning for manufacturing semiconductor devices.

[0257] This specification includes the following inventions.

[0258] [1]: A compound for forming a metal-containing film, characterized in that the compound for forming a metal-containing film has at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms coordinated to the metal atom.

[0259] [2]: The compound for forming a metal-containing film according to the above [1], wherein the polydentate ligand has a structure represented by the following general formulas (1-A) to (1-D): [ka] In the above general formulas (1-A) to (1-D), R1 to R4 are each a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, R5 to R6 are each a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and R7 to R 10 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, R 11 is a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and Y is a divalent organic group having 1 to 10 carbon atoms. The compounds of the above general formulas (1-A) to (1-D) contain at least one or more cyclic ether structures having 2 to 13 carbon atoms. In the above general formula (1-A), R2 and R3 may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms. In the above general formula (1-B), adjacent R5 and R6 may be bonded to each other to form an unsaturated or saturated ring structure. In the above general formula (1-C), adjacent R8 and R9 may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms, or an unsaturated or saturated ring structure.

[0260] [3]: The compound for forming a metal-containing film according to the above [2], wherein the polydentate ligand has a structure represented by the above formula (1-A) or (1-B).

[0261] [4]: The compound for forming a metal-containing film according to any one of the above [1] to [3], wherein the cyclic ether structure is any one of structures represented by the following formulas (a-1) to (a-2): [ka] (In the formula, R a is a hydrogen atom or an organic group having 1 to 10 carbon atoms, and * indicates a bond.

[0262] [5]: The compound for forming a metal-containing film according to any one of the above [2] to [4], characterized in that the compound for forming a metal-containing film is a reaction product of a metal-containing compound containing any one of a metal compound represented by the following formula (2), a hydrolysate or condensate of a metal compound represented by the following formula (2), or a hydrolysis condensate, and a multidentate ligand having a structure represented by the above general formulas (1-A) to (1-D). [ka] (In the formula, M is any one of Ti, Zr, and Hf. L is a monodentate ligand and / or a polydentate ligand having 1 to 30 carbon atoms. X is a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, -NR a R b R is a hydrolyzable group selected from the group consisting of a and R b are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; a+b=4, and a and b are integers of 0 to 4.

[0263] [6]: The compound for forming a metal-containing film according to the above [5], wherein the metal compound represented by the formula (2) has a structure represented by the following formula (3): [ka] (Wherein, M is Ti, Zr, or Hf; R 1A is a monovalent organic group having 1 to 20 carbon atoms.

[0264] [7]: The compound for forming a metal-containing film according to any one of the above [1] to [6], further comprising a ligand derived from a silicon compound represented by the following general formula (4): [ka] (In the above general formula (4), R 3A , R 3B and R 3Cis any organic group selected from an organic group having 1 to 30 carbon atoms and a bridging group having any of the structures represented by the following general formulas (b-1) to (b-3), a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and an aryl group having 1 to 20 carbon atoms. [ka] (In the above general formulas (b-1) to (b-3), R3 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q is 0 or 1, and * is a bond.)

[0265] [8]: A composition for forming a metal-containing film, comprising: (A) the compound for forming a metal-containing film according to any one of the above [1] to [7]; and (B) an organic solvent.

[0266] [9]: The composition for forming a metal-containing film according to the above [8], characterized in that the composition contains one or more of (C) a thermal acid generator and (D) a photoacid generator.

[0267]

[10] : The composition for forming a metal-containing film according to the above [8] or [9], further comprising one or more of (E) a crosslinking agent and (F) a surfactant.

[0268]

[11] : The composition for forming a metal-containing film according to any one of the above [8] to

[10] , wherein the (B) 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.

[0269]

[12] : A method for forming a pattern on a workpiece substrate, comprising: (I-1) applying a metal-containing film-forming composition according to any one of the above [8] to

[11] onto a workpiece substrate, followed by heat treatment to form a metal-containing film; (I-2) forming a resist upper layer film on the metal-containing film using a photoresist material; (I-3) exposing the resist upper layer film to a pattern and developing it with a developer to form a pattern in the resist upper layer film; (I-4) transferring the pattern to the metal-containing film by dry etching using the resist upper layer film on which the pattern has been formed as a mask; and (I-5) processing the workpiece substrate using the metal-containing film on which the pattern has been formed as a mask to form a pattern on the workpiece substrate.

[0270]

[13] : A method for forming a pattern on a substrate to be processed, comprising: (II-1) forming a resist underlayer film on the substrate to be processed; (II-2) applying a metal-containing film-forming composition according to any one of the above [8] to

[11] on the resist underlayer film, followed by heat treatment to form a metal-containing film; (II-3) forming a resist upperlayer film on the metal-containing film using a photoresist material; (II-4) pattern-exposing the resist upperlayer film and developing it with a developer to form a pattern on the resist upperlayer film; (II-5) using the resist upperlayer film on which the pattern has been formed as a mask to transfer a pattern to the metal-containing film by dry etching; (II-6) using the metal-containing film on which the pattern has been transferred as a mask to transfer a pattern to the resist underlayer film by dry etching; 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.

[0271] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention. [Explanation of symbols]

[0272] 1...substrate, 2...processed layer, 2a...pattern (pattern formed on the processed layer), 3...organic resist underlayer film, 3a...organic resist underlayer film pattern, 4...metal-containing film, 4a...metal-containing film pattern, 5...resist upper layer film, 5a...resist upper layer film pattern, 6...Exposed part, 10...Substrate to be processed.

Claims

1. A compound for forming a metal-containing film, characterized in that the compound for forming a metal-containing film has at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a polydentate ligand containing a cyclic ether structure having 2 to 13 carbon atoms coordinated to the metal atom.

2. 2. The compound for forming a metal-containing film according to claim 1, wherein the polydentate ligand has a structure represented by the following general formulas (1-A) to (1-D). 【Chemistry 1】 (In the above general formulas (1-A) to (1-D), R １ ~R ４ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, R ５ ~R ６ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, R ７ ~R １０ is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, R １１ is a monovalent organic group having 1 to 20 carbon atoms which may contain a cyclic ether structure having 2 to 13 carbon atoms, and Y is a divalent organic group having 1 to 10 carbon atoms. The compounds of the above general formulas (1-A) to (1-D) contain at least one cyclic ether structure having 2 to 13 carbon atoms. In the above general formula (1-A), R ２ and R ３ may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms. ５ and R ６ may be bonded to each other to form an unsaturated or saturated ring structure. ８ and R ９ may be bonded to each other to form a cyclic ether structure having 2 to 13 carbon atoms, or an unsaturated or saturated ring structure.

3. 3. The compound for forming a metal-containing film according to claim 2, wherein the polydentate ligand has a structure represented by the above formula (1-A) or (1-B).

4. 2. The compound for forming a metal-containing film according to claim 1, wherein the cyclic ether structure is any one of structures represented by the following formulas (a-1) to (a-2): 【Chemistry 2】 (In the formula, R ａ is a hydrogen atom or an organic group having 1 to 10 carbon atoms, and * indicates a bond.)

5. The compound for forming a metal-containing film according to claim 2, characterized in that the compound for forming a metal-containing film is a reaction product of a metal-containing compound containing any one of a metal compound represented by the following formula (2), a hydrolysate or condensate of a metal compound represented by the following formula (2), or a hydrolysis condensate, and a multidentate ligand having a structure represented by any one of the general formulas (1-A) to (1-D). 【Chemistry 3】 (In the formula, M is any one of Ti, Zr, and Hf. L is a monodentate ligand and / or a polydentate ligand having 1 to 30 carbon atoms. X is a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, -NR a R b R is a hydrolyzable group selected from ａ and R ｂ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; a+b=4, and a and b are integers from 0 to 4.

6. 6. The compound for forming a metal-containing film according to claim 5, wherein the metal compound represented by formula (2) has a structure represented by the following formula (3): 【Chemistry 4】 (Wherein, M is Ti, Zr, or Hf; R １Ａ is a monovalent organic group having 1 to 20 carbon atoms.

7. The compound for forming a metal-containing film according to claim 1, further comprising a ligand derived from a silicon compound represented by the following general formula (4): 【Chemistry 5】 (In the above general formula (4), R ３Ａ , R ３Ｂ and R ３Ｃ is any one of organic groups selected from an organic group having 1 to 30 carbon atoms and a crosslinking group having any one of the structures represented by the following general formulas (b-1) to (b-3), a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and an aryl group having 1 to 20 carbon atoms. 【Chemistry 6】 (In the above general formulas (b-1) to (b-3), R ３ is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q is 0 or 1, and * is a bond.

8. A metal-containing film-forming composition comprising: (A) the compound for forming a metal-containing film according to any one of claims 1 to 7, and (B) Organic solvent A composition for forming a metal-containing film, comprising:

9. 9. The metal-containing film-forming composition according to claim 8, wherein the composition contains at least one of (C) a thermal acid generator and (D) a photoacid generator.

10. The metal-containing film-forming composition according to claim 8 , further comprising at least one of (E) a crosslinking agent and (F) a surfactant.

11. The metal-containing film-forming composition according to claim 8, characterized in that the (B) 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.

12. A method for forming a pattern on a workpiece substrate, comprising the steps of: (I-1) A step of applying the composition for forming a metal-containing film according to claim 8 onto a substrate to be processed, followed by heat treatment to form a metal-containing film; (I-2) forming a resist top layer film on the metal-containing film using a photoresist material; (I-3) a step of pattern-exposing 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 metal-containing film by dry etching using the resist top layer film on which the pattern is formed as a mask; and (I-5) A step of processing the substrate to be processed using the metal-containing film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. A pattern forming method comprising the steps of:

13. A method for forming a pattern on a workpiece substrate, comprising the steps of: (II-1) forming a resist underlayer film on a substrate to be processed; (II-2) A step of forming a metal-containing film by applying the composition for forming a metal-containing film according to claim 8 onto the resist underlayer film and then performing a heat treatment; (II-3) forming a resist top layer film on the metal-containing film using a photoresist material; (II-4) a step of forming a pattern on the resist upper layer film by pattern-exposing the resist upper layer film and then developing the resist upper layer film with a developer; (II-5) a step of transferring a pattern to the metal-containing film by dry etching using the resist top layer film on which the pattern has been formed as a mask; (II-6) a step of transferring a pattern to the resist underlayer film by dry etching using the metal-containing film to which the pattern has been transferred as a mask; (II-7) 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; A pattern forming method comprising the steps of:

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