Metal-containing film-forming compound, metal-containing film-forming composition, and pattern forming method

Abstract

The invention relates to a compound for forming a metal-containing film, a composition for forming a metal-containing film, and a pattern forming method. The invention provides a metal-containing forming compound, a metal-containing forming composition and a pattern forming method, wherein the metal-containing forming compound can obtain a good pattern shape in a fine patterning process in a semiconductor device manufacturing step, has high sealing performance with a resist upper layer film, and can inhibit fine pattern collapse. The present invention is a compound for forming a metal-containing film, the compound containing at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand that coordinates with the metal atom via an oxygen atom, the ligand having a ring structure (t), the ring structure (t) is selected from the group consisting of a ring having 4 or more carbon atoms and containing one or more oxygen atoms, a ring having 3 or more carbon atoms and containing two or more oxygen atoms, and a ring having 3 or more carbon atoms and containing one or more oxygen atoms and one or more heteroatoms different from the oxygen atoms.

Description

TECHNICAL FIELD

[0001] The present application relates to a metal-containing film forming compound, a metal-containing film forming composition using the same, and a pattern forming method using the same. BACKGROUND

[0002] With the high integration and high speed of LSIs, the miniaturization of pattern size is rapidly progressing. In order to cope with this miniaturization, the photolithography technology has achieved the formation of fine patterns by the shortening of the wavelength of the light source and the appropriate selection of the resist composition. The center of attention is a positive type photoresist composition used as a single layer. This single layer positive type photoresist composition has a switching mechanism in which the skeleton in the resist resin has etch resistance to dry etching by gas plasma of chlorine or fluorine, and the exposed portion is dissolved, whereby the exposed portion is dissolved to form a pattern, and the remaining resist pattern is used as an etching mask to perform dry etching processing on the substrate to be processed.

[0003] However, in the case where the film thickness of the photoresist film used is directly miniaturized, that is, the pattern width is made smaller, the resolution of the photoresist film can be reduced, and when the photoresist film is subjected to pattern development using a developer, the so-called aspect ratio becomes too large, and as a result, the problem of causing pattern collapse occurs. Therefore, the photoresist film is thinned as the pattern is miniaturized.

[0004] On the other hand, in the processing of the substrate to be processed, a method of using a photoresist film having a pattern formed as an etching mask and processing the substrate by dry etching is generally used, but there is no dry etching method that can achieve complete 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 collapses in the processing of the substrate, and the resist pattern cannot be correctly transferred to the substrate to be processed. Therefore, as the pattern is miniaturized, higher dry etching resistance is required for the resist composition. However, on the other hand, in order to improve the resolution, a resin having a small light absorption at the exposure wavelength is required for the resin used in the photoresist composition. Therefore, as the exposure light is shortened to i-ray, KrF, ArF, the resin is also changed to novolak resin, polyhydroxystyrene, and a resin having an aliphatic polycyclic skeleton, but in reality, the etching rate in the dry etching conditions in the processing of the substrate is fast, and the recent photoresist composition having high resolution has a tendency to have weak etching resistance.

[0005] Therefore, it becomes necessary to perform dry etching processing on the substrate to be processed using a thinner photoresist film having weaker etching resistance, and the securing of the material and the process in this processing step becomes urgent.

[0006] One of the methods for solving such problems is a multi-layer resist method. This method is a method in which an etching selectivity-different resist intermediate film is interposed between a resist upper film and a substrate to be processed, and after the resist upper film is patterned, the resist upper film pattern is used as a dry etching mask to transfer the pattern to the resist intermediate film by dry etching, and further the resist intermediate film is used as a dry etching mask to transfer the pattern to the substrate to be processed by dry etching.

[0007] One of the multi-layer resist methods is a 3-layer resist method that can be implemented using a general resist composition used in a single-layer resist method. In this 3-layer resist method, for example, an organic film composed of a novolak resin or the like is formed as a resist lower film on a substrate to be processed, a silicon-containing resist intermediate film is formed thereon as a resist intermediate film, and a general organic photoresist film is formed thereon as a resist upper film. When dry etching by fluorine-based gas plasma is performed, the organic resist upper film can achieve a good etching selectivity with respect to the silicon-containing resist intermediate film, and thus the resist upper film pattern can be transferred to the silicon-containing resist intermediate film by dry etching by fluorine-based gas plasma. According to this method, even if a resist composition that is difficult to form a pattern having a sufficient film thickness to directly process the substrate to be processed, or a resist composition that does not have sufficient dry etching resistance for processing the substrate, is used, a pattern can be transferred to the silicon-containing resist intermediate film (resist intermediate film), and then, if pattern transfer by dry etching by oxygen-based or hydrogen-based gas plasma is performed, a pattern of an organic film composed of a novolak resin or the like (resist lower film) having sufficient dry etching resistance for processing the substrate can be obtained. As the resist lower film as described above, for example, those described in Patent Document 1 and the like are known, and many resist lower films are known.

[0008] As the silicon-containing resist intermediate film used in the 3-layer resist method as described above, a silicon-containing inorganic film made by CVD, such as a SiO2 film (for example, Patent Document 2), a SiON film (for example, Patent Document 3), can be used, and as a film that can be obtained by spin coating, a SOG (spin on glass) film (for example, Patent Document 4, Non-Patent Document 1), a cross-linkable silsesquioxane film (for example, Patent Document 5), and the like can be used, and a polysilane film (for example, Patent Document 6) can also be used. Among these, the SiO2 film and the SiON film have high performance as a dry etching mask when dry etching the lower organic film, but a special device is required for film formation. In contrast, the SOG film, the cross-linkable silsesquioxane film, and the polysilane film can be formed only by spin coating and heating, and it is considered that the process efficiency is high.

[0009] The silicon-containing films conventionally used in such multilayer resist methods have several problems. For example, it is known that when attempting to form resist patterns using optical lithography, the exposure light is reflected from the substrate and interferes with the incident light, causing the so-called standing wave problem. To obtain fine patterns with no edge roughness in the resist film using state-of-the-art ArF wetting and high-NA exposure conditions, the intermediate film needs anti-reflection properties. Furthermore, as the state-of-the-art semiconductor processes mentioned above are increasingly focused on thinning photoresists, thinning of the intermediate film is also required. In next-generation exposure processes, there is a demand for anti-reflection effects with film thicknesses below 30 nm. Also, for the dry etching rate of oxygen plasma commonly used in processing the lower resist layer, a smaller etch selectivity is preferred to improve the etch selectivity between the intermediate and lower layers. Due to the trend towards thinner films, improved dry etching resistance of the intermediate film is required.

[0010] For resist interlayers that meet the requirements for such anti-reflective properties and dry etching characteristics, metal hard mask films containing Ti or Zr have attracted attention, replacing conventional silicon-containing films. TiO2 and ZrO2 are known as high-refractive-index materials, and by including them in the film, the anti-reflective effect can be improved under high NA exposure conditions. Furthermore, by containing metal-oxygen bonds, excellent dry etching resistance to oxygen gases can be expected.

[0011] Furthermore, metal hard mask films not only exhibit excellent resistance to dry etching of oxygen gas, but also excellent resistance to dry etching of fluorine gas. Therefore, it is also possible to expect a two-layer resist method in which a metal hard mask film is used as the lower resist film on the substrate being processed, and an upper resist film is formed on it.

[0012] On the other hand, when such a hard metal mask film is used directly beneath the top layer of the photoresist, improving the adhesion between the hard metal mask film and the photoresist pattern becomes a challenge. The hard metal mask film, after curing, has a higher surface energy (or a lower water contact angle) than the subsequently applied photoresist. This surface energy mismatch can cause poor adhesion between the hard metal mask film and the subsequently applied photoresist, leading to pattern collapse.

[0013] In order to suppress collapse of a photoresist pattern on a metal hard mask film, surface modification of the metal hard mask film is required, for example, a metal hard mask containing a surface-modified organic polymer is reported in Patent Literature 7. It is reported that adhesiveness to a resist pattern is improved by using a difference in free energy between an organic polymer and a metal compound to cause the organic polymer to be biased to the surface layer. In order to suppress pattern collapse, an organic polymer containing a surface treatment moiety selected from the group consisting of a hydroxyl group, a protected hydroxyl group, a protected carboxyl group, and a mixture thereof is used. However, under the current circumstances where more fine pattern formation is required, these materials cannot be said to have sufficient pattern collapse suppression performance. Also, because of the presence of the organic polymer, there is a concern that dry etching resistance to oxygen gas will be deteriorated, and therefore a metal-containing film-forming compound having excellent adhesiveness to a resist upper layer film is sought to be developed.

[0014] Recently, the interaction of a resist upper layer film with a lower layer film directly below the resist upper layer film in a fine pattern also has an influence on the sensitivity of the resist, the shape of the pattern (rectangularity and pitch residue), and the like, and from these viewpoints, the lower layer film directly below the resist upper layer film is also required to have improved performance (Non-Patent Literature 2).

[0015] Prior Art Documents

[0016] Patent Literature

[0017] [Patent Literature 1] Japanese Patent Application Laid-Open (JP-A) No. 2004-205685

[0018] [Patent Literature 2] Japanese Patent Application Laid-Open (JP-A) No. H7-183194

[0019] [Patent Literature 3] Japanese Patent Application Laid-Open (JP-A) No. H7-181688

[0020] [Patent Literature 4] Japanese Patent Application Laid-Open (JP-A) No. H5-291208

[0021] [Patent Literature 5] Japanese Patent Application Laid-Open (JP-A) No. 2005-520354

[0022] [Patent Literature 6] Japanese Patent Application Laid-Open (JP-A) No. Hl l-60735

[0023] [Patent Literature 7] Japanese Patent (JP-B) No. 6463600

[0024] Non-Patent Literature

[0025] [Non-Patent Literature 1] J. Appl. Polym. Sci., Vol. 88, 636-640 (2003)

[0026] [Non-Patent Literature 2] Proc. SPIE Vol. 7273, 72731J (2009) SUMMARY

[0027] [Problems to be Solved by the Invention]

[0028] The present invention has been made in view of the above circumstances, and aims to provide a metal-containing film forming compound for a resist intermediate film which provides a good pattern shape in a fine patterning process in a semiconductor device manufacturing step, and has high adhesiveness to a resist upper layer film and suppresses collapse of a fine pattern, a metal-containing film forming composition using the same, and a pattern forming method using the same.

[0029] [Means for Solving the Problems]

[0030] To solve the above problems, a metal-containing film forming compound for a resist intermediate film is provided in the present invention,

[0031] The aforementioned metal-containing film forming compound for a resist intermediate film contains at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the aforementioned metal atom via an oxygen atom,

[0032] The aforementioned ligand has a ring structure (t) selected from a ring having a carbon number of 4 or more containing one or more oxygen atoms,

[0033] a ring having a carbon number of 3 or more containing two or more oxygen atoms, and a ring having a carbon number of 3 or more containing one or more oxygen atoms and one or more heteroatoms different from the oxygen atoms.

[0034] If the metal-containing film forming compound for a resist intermediate film is as described above, when used in a metal-containing film forming composition, the adhesiveness to a resist upper layer film can be improved, and the shape of a resist pattern after exposure and development becomes rectangular. By this means, substrate processing by a fine pattern can be performed.

[0035] The aforementioned ring structure (t) is preferably a structure containing a ring having a carbon number of 4 or more containing two or more oxygen atoms, or a ring having a carbon number of 4 or more containing one or more oxygen atoms and one or more heteroatoms different from the oxygen atoms.

[0036] If the metal-containing film forming compound for a resist intermediate film is as described above, when used in a metal-containing film forming composition, the adhesiveness to a resist upper layer film can be more improved, and the shape of a resist pattern after exposure and development becomes rectangular. By this means, substrate processing by a fine pattern can be performed.

[0037] The aforementioned ring structure (t) is preferably a polycyclic structure formed by bonding one or more of a cyclic hydrocarbon group having a carbon number of 4 to 6 which can also contain a heteroatom, a cyclic hydrocarbon group having a carbon number of 5 to 6 which can also contain a heteroatom and has one or more carbon-carbon double bonds, an aromatic ring, or an aromatic heterocycle.

[0038] If the compound is such a metal-containing film-forming compound, when used in a metal-containing film-forming composition, heat resistance is improved, and adhesion to a resist overcoat film can be further improved, and the shape of a resist pattern after exposure and development becomes rectangular. By this, substrate processing by a fine pattern can be performed.

[0039] The aforementioned ring structure (t) is more desirable from the viewpoint of the organic acid containing the aforementioned ring structure (t).

[0040] If the ligand is such, a strong coordination effect to a metal atom is exhibited, so when used in a metal-containing film-forming composition, a composition with excellent storage stability can be provided.

[0041] The aforementioned organic acid is more desirable from the viewpoint of the carboxylic acid.

[0042] If the ligand is such, a strong coordination effect to a metal atom is exhibited, so when used in a metal-containing film-forming composition, a composition with excellent storage stability can be provided. Also, it is more desirable from the viewpoint of raw material procurement.

[0043] The aforementioned ligand is more desirable from the viewpoint of the following structure.

[0044] [Chemical Formula 1]

[0045] Ra(X)nCOOH (1)

[0046] In the formula, Ra is a monovalent organic group containing the aforementioned ring structure (t), X is a group selected from a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted branched alkylene group having 3 to 10 carbon atoms, a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms containing a carbon-carbon double bond, a substituted or unsubstituted branched alkylene group having 3 to 10 carbon atoms containing a carbon-carbon double bond, and n is 0 or 1.

[0047] If the compound is such a metal-containing film-forming compound, when used in a metal-containing film-forming composition, adhesion to a resist overcoat film can be further improved, and the shape of a resist pattern after exposure and development becomes rectangular. By this, substrate processing by a fine pattern can be performed.

[0048] The aforementioned metal-containing film-forming compound is more desirable from the viewpoint of further containing a ligand from a silicon compound represented by the following general formula (w).

[0049] [Chemical Formula 2]

[0050]

[0051] In the formula, R A , R B , and R Can organic group having a carbon number of 2 to 30 for a crosslinking group of any of the structures represented by the following general formulae (w-1) to (w-3), an organic group selected from a substituted or unsubstituted alkyl group having a carbon number of 1 to 20, and an aryl group having a carbon number of 6 to 20.

[0052] [Chemical Formula 3]

[0053]

[0054] In the above general formulae (w-1) to (w-3), Rs is a hydrogen atom or a monovalent organic group having a carbon number of 1 to 10, q represents 0 or 1, and * represents a bonding portion.

[0055] By using the aforementioned compound, the stability in a solution of the aforementioned metal compound can be improved.

[0056] The aforementioned metal-containing film-forming compound is preferably a reaction product of a metal compound represented by the following formula (a) or a metal-containing compound including any of a hydrolyzate, a condensate, and a hydrolysis condensate of the metal compound represented by the following formula (a) and a compound having the aforementioned ring structure (t).

[0057] [Chemical Formula 4]

[0058] L a MX b (a)

[0059] In the formula, M is any of Ti, Zr, and Hf. L is a monodentate ligand or a polydentate ligand having a carbon number of 1 to 30, and X is a hydrolyzable group selected from a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, and -NR 1 R 2 R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group having a carbon number of 1 to 20. a + b = 2 to 4, and a and b are integers of 0 to 4.

[0060] By using such a metal compound, a metal-containing film having more excellent dry etching resistance to fluorine gas and oxygen gas can be formed.

[0061] The aforementioned formula (a) is preferably a structure of the following formula (a-1).

[0062] [Chemical Formula 5]

[0063] M(OR 1A )4 (a-1)

[0064] In the formula, M is any of Ti, Zr, and Hf, and R 1A is a monovalent organic group having a carbon number of 1 to 20.

[0065] If the metal compound is of such a structure, it is more desirable in terms of productivity and procurement of raw materials.

[0066] Further, the present application provides a metal-containing film forming composition which functions as a metal-containing film material used in semiconductor production, comprising: the aforementioned (A) metal-containing film forming compound and (B) organic solvent.

[0067] If the metal-containing film forming composition is of such a structure, a metal-containing film having excellent dry etching resistance to conventional resist underlayer film materials and excellent wet stripping properties can be formed.

[0068] The aforementioned composition can further contain one or more of (C) crosslinking agent, (D) acid generator, and (E) surfactant.

[0069] If the metal-containing film forming composition contains the aforementioned additive, it becomes a metal-containing film forming composition having more excellent coating properties, dry etching resistance, and embedding and / or planarization properties.

[0070] It is more desirable that the aforementioned (B) organic solvent contains one or more organic solvents having a boiling point of 180°C or higher as (B1) high-boiling-point solvent.

[0071] By imparting flowability to the aforementioned metal-containing film forming compound due to the addition of high-boiling-point solvent, the occurrence of coating defects due to drying of the metal-containing film forming composition can be suppressed.

[0072] Further, the present application provides a pattern forming method which is a method of forming a pattern on a processed substrate, comprising the following steps:

[0073] (I-1) after coating the metal-containing film forming composition of the present application on a processed substrate directly or indirectly, performing heat treatment, thereby forming a metal-containing film;

[0074] (I-2) forming a resist upper layer film directly or indirectly on the aforementioned metal-containing film using a photoresist material;

[0075] (I-3) after performing pattern exposure on the aforementioned resist upper layer film, performing development with a developer, thereby forming a pattern on the aforementioned resist upper layer film;

[0076] (I-4) using the aforementioned pattern-formed resist upper layer film as a mask, directly or indirectly transferring the pattern to the aforementioned metal-containing film by dry etching; and

[0077] (I-5) using the aforementioned metal-containing film having a pattern as a mask, and directly or indirectly processing the aforementioned processed substrate to form a pattern on the aforementioned processed substrate.

[0078] Such a pattern forming method can be desirably used in a pattern forming method such as a multilayer resist process.

[0079] Further, the pattern forming method of the present application can include at least one organic resist underlayer film between the aforementioned processed substrate and the metal-containing film.

[0080] If such a pattern forming method is used, a pattern can be transferred to a processed substrate with high precision.

[0081] Further, the pattern forming method of the present application is preferably a method in which a resist upper layer film is formed directly on the aforementioned metal-containing film.

[0082] A metal-containing film formed using the metal-containing film forming compound of the present application has excellent adhesion to a resist upper layer film, and thus a resist upper layer film pattern having high rectangularity can be obtained.

[0083] Further, the pattern forming method of the present application can include a step of removing the aforementioned metal-containing film with a chemical liquid after a step of forming a pattern by using the aforementioned metal-containing film as a mask and processing a film directly below the aforementioned metal-containing film.

[0084] If such a pattern forming method is used, damage to a substrate can be suppressed and the aforementioned metal-containing film can be easily removed, and thus a pattern having excellent rectangularity in cross-sectional shape can be formed.

[0085] It is desirable to use a solution containing hydrogen peroxide water and an acid, or a solution containing a base, hydrogen peroxide water, and water as the aforementioned chemical liquid.

[0086] If such a chemical liquid is used, a metal-containing film formed using the metal-containing film forming compound of the present application can be easily removed.

[0087] [Effects of the Invention]

[0088] As described above, the metal-containing film forming compound of the present application contains a ligand having a specific ring structure (t), and thus when a metal-containing film is formed using the same, adhesion to a resist upper layer film can be improved, and the shape of a resist pattern after exposure and development becomes rectangular. Therefore, if a metal-containing film forming composition using the aforementioned metal-containing film forming compound, and a pattern forming method using the same are used, the same can be desirably used in a pattern forming method such as a multilayer resist process. BRIEF DESCRIPTION OF DRAWINGS

[0089] [ Figure 1 ]Figure 1 (I-A) to (I-I) are explanatory diagrams of an example (3-layer resist process) of the pattern forming method of the present application.

[0090] [ Figure 2 ] Figure 2 (I-A) to (I-I) are explanatory diagrams of an example (3-layer resist process) of the pattern forming method of the present application. DETAILED DESCRIPTION

[0091] As explained above, a metal-containing film forming compound having high adhesiveness to an upper resist film and having a collapse suppressing effect for a fine pattern, a metal-containing film forming composition using the same, and a pattern forming method using the same are sought to be developed.

[0092] A metal-containing film formed using a conventional metal-containing film forming compound has a higher surface energy (or a smaller water contact angle) than a photoresist to be applied next, and thus mismatch of the surface energy causes adhesion failure between the metal-containing film and the photoresist to be applied next, resulting in pattern collapse. Also, in the case where an organic polymer is mixed as a surface modifier, dry etching resistance during processing of an organic underlayer film becomes insufficient, and there is a concern that pattern transfer failure is induced.

[0093] The present inventors have made earnest research in view of the above problems, and as a result, have found that the above problems can be solved by a metal-containing film forming compound including a ligand having a specific structure, a metal-containing film forming composition using the same, and a pattern forming method using the same, and have completed the present application.

[0094] That is, the present application is a metal-containing film forming compound,

[0095] The aforementioned metal-containing film forming compound includes at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the aforementioned metal atom via an oxygen atom,

[0096] The aforementioned ligand has a ring structure (t) selected from a ring having a carbon number of 4 or more including one or more oxygen atoms,

[0097] a ring having a carbon number of 3 or more including two or more oxygen atoms, and a ring having a carbon number of 3 or more including one or more oxygen atoms and one or more heteroatoms different from the oxygen atom.

[0098] Hereinafter, the present application will be described in detail, but the present application is not limited to these.

[0099] <metal-containing film forming compound>

[0100] The present application is a metal-containing film forming compound,

[0101] The aforementioned metal-containing film-forming compound contains at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the aforementioned metal atom via an oxygen atom,

[0102] The aforementioned ligand has a ring structure (t) selected from a ring having 4 or more carbon atoms containing one or more oxygen atoms,

[0103] a ring having 3 or more carbon atoms containing two or more oxygen atoms, and a ring having 3 or more carbon atoms containing one or more oxygen atoms and one or more heteroatoms different from oxygen atoms.

[0104] Here, in the ring structure (t), the number of carbon atoms in the ring having 4 or more carbon atoms containing one or more oxygen atoms and the like means the number of carbon atoms directly contributing to the formation of one ring structure containing oxygen atoms, and does not include the number of carbon atoms contributing to the formation of an adjacent ring structure.

[0105] The aforementioned ring structure (t) is a structure selected from a ring having 4 or more carbon atoms containing one or more oxygen atoms, a ring having 3 or more carbon atoms containing two or more oxygen atoms, and a ring having 3 or more carbon atoms containing one or more oxygen atoms and one or more heteroatoms different from oxygen atoms, and is preferably a ring structure having 4 to 6 carbon atoms. It can also have one or more unsaturated bonds in the ring structure, and can be a ring structure corresponding to a heteroaromatic ring. If it is such a ring structure, it is more desirable because it can provide a metal compound having excellent storage stability in a composition.

[0106] If it is such a metal compound, when used in a metal-containing film-forming composition, it can form a metal-containing film having excellent dry etching resistance to a conventional resist underlayer film material and excellent adhesion to a resist overlayer film.

[0107] As for the desirable structure of the aforementioned ring structure (t), the following can be exemplified.

[0108] [Chemical Formula 6]

[0109]

[0110] The above-mentioned ligand is preferably one having a ring structure (t) selected from a ring having 4 or more carbon atoms containing 1 or more oxygen atoms, a ring having 3 or more carbon atoms containing 2 or more oxygen atoms, and a ring having 3 or more carbon atoms containing 1 or more oxygen atoms and 1 or more heteroatoms other than oxygen atoms. More preferably, the above-mentioned ligand has a ring structure (t-1) containing 2 or more oxygen atoms or a ring structure (t-1) containing 1 or more oxygen atoms and 1 or more heteroatoms other than oxygen atoms. That is, the above-mentioned ring structure (t) is preferably one including a ring having 4 or more carbon atoms containing 2 or more oxygen atoms or a ring having 4 or more carbon atoms containing 1 or more oxygen atoms and 1 or more heteroatoms other than oxygen atoms.

[0111] By virtue of the above-mentioned ligand containing the above-mentioned ring structure (t-1), the adhesion to the resist overcoat film can be further improved, and an excellent resist pattern shape can be formed when developed with an alkali developer or an organic developer, and a rectangular resist pattern can be transferred to the lower layer by subsequent dry etching. As to the heteroatoms other than oxygen atoms, there is no particular limitation, and they are preferably nitrogen atoms or sulfur atoms, and more preferably nitrogen atoms.

[0112] The above-mentioned ring structure (t) is preferably bonded to any one or more of a cyclic hydrocarbon group having 4 to 6 carbon atoms which can also contain heteroatoms, a cyclic hydrocarbon group having 5 to 6 carbon atoms which can also contain heteroatoms and has 1 or more carbon-carbon double bonds, an aromatic ring, or an aromatic heterocycle to form a polycyclic structure. As to the above-mentioned polycyclic structure, condensed rings, bicyclic systems, tricyclic systems, condensed rings containing a bridged structure, condensed rings containing a bridged ring containing heteroatoms, spiro rings, and the like can be exemplified.

[0113] By virtue of the above-mentioned ligand containing a polycyclic structure, the heat resistance can be improved, and the adhesion to the resist overcoat film can be further improved.

[0114] It is preferable that the above-mentioned polycyclic structure does not contain an anhydride unit. If the polycyclic structure does not contain an anhydride unit, there is no risk that the anhydride structure will open and coordinate with a metal atom during the synthesis of a metal compound, and thus, when used in a composition for forming a metal-containing film, there is no problem in terms of the adhesion to the resist overcoat film.

[0115] It is preferable that the above-mentioned ligand be derived from an organic acid. That is, it is preferable that the above-mentioned ring structure (t) be derived from an organic acid containing the above-mentioned ring structure (t). As to the organic acid, it is preferably any one of a carboxylic acid, a sulfonic acid, a phosphinic acid, and a phosphonic acid, and more preferably a carboxylic acid in view of the coordination effect with a metal atom and the availability of raw materials, and more specifically, it is preferable to be derived from the following structure.

[0116] [Chemical Formula 7]

[0117] Ra(X) n COOH (1)

[0118] In the above formula, Ra is a monovalent organic group containing the aforementioned ring structure (t), X is a group selected from a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted branched alkylene group having 3 to 10 carbon atoms, a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms containing a carbon-carbon double bond, a substituted or unsubstituted branched alkylene group having 3 to 10 carbon atoms containing a carbon-carbon double bond, and n is 0 or 1.

[0119] In the above formula (1), X is a group selected from a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted branched alkylene group having 3 to 10 carbon atoms, a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms containing a carbon-carbon double bond, a substituted or unsubstituted branched alkylene group having 3 to 10 carbon atoms containing a carbon-carbon double bond, preferably a substituted or unsubstituted straight-chain alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms containing a carbon-carbon double bond, more preferably an unsubstituted alkylene group having 1 to 5 carbon atoms.

[0120] As for the ideal structure of Ra in the above formula (1), the following can be shown.

[0121] [Chemical Formula 8]

[0122]

[0123] The above indicates the bonding portion to X.

[0124] From the viewpoint of raw material procurement, in the above formula (1), n is more ideal as 0.

[0125] The aforementioned metal-containing film-forming compound is more ideal as a reaction product of a metal compound represented by the following formula (a), or a metal-containing compound containing any of a hydrolyzate, a condensate, and a hydrolysis condensate of the metal compound represented by the following formula (a) and a compound having the aforementioned ring structure (t).

[0126] [Chemical Formula 9]

[0127] L a MX b (a)

[0128] In the formula, M is any of Ti, Zr, and Hf. L is a monodentate ligand or a polydentate ligand having 1 to 30 carbons, and X is a hydrolyzable group selected from a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, and -NR 1 R 2 R and R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbons. a + b = 2 to 4, and a and b are integers from 0 to 4.

[0129] If the compound for forming a metal-containing film is such, when used in a composition for forming a metal-containing film, a metal-containing film having excellent dry etching resistance to fluorine gas and oxygen gas can be formed.

[0130] [(a) metal-containing compound]

[0131] (hydrolyzable group)

[0132] As the hydrolyzable group X of the above formula (a), for example, a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, and an -NR 1 R 2 R 1 R 2 Each of R and R is desirably a hydrogen atom or a monovalent organic group having a carbon number of 1 to 20.

[0133] As the halogen atom, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like can be mentioned.

[0134] As the alkoxy group, for example, a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a t-butoxy group, and the like can be mentioned.

[0135] As the carboxylate group, an acetate group, a propionate group, a butyrate group, an n-hexane carboxylate group, an n-octane carboxylate group, and the like can be mentioned.

[0136] As the acyloxy group, for example, an acetoxy group, an acetyloxy group, a propionyloxy group, a butyryloxy group, a t-butyryloxy group, a t-amylcarbonyloxy group, an n-hexane carbonyloxy group, an n-octane carbonyloxy group, and the like can be mentioned.

[0137] As the -NR 1 R 2 For example, an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dipropylamino group, and the like can be mentioned.

[0138] As the hydrolyzable group X, an alkoxy group is preferable, and an i-propoxy group, an n-butoxy group, or a t-butoxy group is more preferable.

[0139] (monodentate ligand)

[0140] As the monodentate ligand, for example, a hydroxyl ligand, a carboxyl ligand, an amide ligand, an amine ligand, an ammonia ligand, an olefin ligand, and the like can be mentioned.

[0141] As the amide ligand, for example, an unsubstituted amide ligand (NH2), a methylamide ligand (NHMe), a dimethylamide ligand (NMe2), a diethylamide ligand (NEt2), a dipropylamide ligand (NPr2), and the like can be mentioned.

[0142] As the amine ligand, for example, pyridine, trimethylamine ligand, piperidine ligand, and the like can be exemplified.

[0143] As the olefin ligand, for example, chain olefins such as ethylene, propylene, and the like, cyclic olefins such as cyclopentene, cyclohexene, norbornene, and the like can be exemplified.

[0144] (polydentate ligand)

[0145] As the polydentate ligand, for example, ligands from hydroxy acid esters, ligands from β-diketones, ligands from β-keto esters, ligands from α,α-dicarboxylic acid esters, hydrocarbons having a π bond, diphosphines, and the like can be exemplified.

[0146] As the hydroxy acid ester, for example, glycolate, lactate, 2-hydroxycyclohexane-1-carboxylate, salicylate, and the like can be exemplified.

[0147] As the β-diketone, for example, acetylacetone, α-alkyl-substituted acetylacetone, β-ketopentanoic acid ester, benzoylacetone, 1,3-propanedione, and the like can be exemplified.

[0148] As the α,α-dicarboxylic acid ester, for example, malonic acid diester, α-alkyl-substituted malonic acid diester, α-cycloalkyl-substituted malonic acid diester, α-aryl-substituted malonic acid diester, and the like can be exemplified.

[0149] As the hydrocarbon having a π bond, for example, chain dienes such as butadiene, isoprene, and the like, cyclic dienes such as cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene, norbornadiene, and the like, aromatic hydrocarbons such as benzene, toluene, xylene, hexamethylbenzene, naphthalene, indene, and the like can be exemplified.

[0150] As the diphosphine, for example, 1,1-bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl, 1,1'-bis(diphenylphosphino)ferrocene, and the like can be exemplified.

[0151] In the above general formula (a), a+b = 2 to 4, and a and b are integers of 0 to 4. As for a, it is preferably 0 to 4, and more preferably 2 or 4. As for b, it is preferably 0 to 4, and more preferably 0 or 2 or 4. By setting a and b to the above range, the stability of the metal-containing film formation compound can be improved.

[0152] As the ideal example of the metal compound represented by formula (a), the following can be exemplified.

[0153] Examples of titanium-containing compounds include diisopropoxybis(2,4-pentanedione)titanium (IV), tetra-n-butoxytitanium (IV), tetra-n-propoxytitanium (IV), tetraisopropoxytitanium (IV), tri-n-butoxy monostearate titanium (IV), butoxytitanium (IV) oligomer, aminopropyltrimethoxytitanium (IV), triethoxymono(2,4-pentanedione)titanium (IV), tri-n-propoxymono(2,4-pentanedione)titanium (IV), triisopropoxymono(2,4-pentanedione)titanium, and di-n-butoxybis(2,4-pentanedione)titanium (IV).

[0154] Examples of zirconium-containing compounds include dibutoxybis(ethyl acetoacetate)zirconium (IV), di-n-butoxybis(2,4-pentanedione)zirconium (IV), tetra-n-butoxyzirconium (IV), tetra-n-propoxyzirconium (IV), tetra-isopropoxyzirconium (IV), aminopropyltriethoxyzirconium (IV), 2-(3,4-epoxycyclohexyl)ethyltrimethoxyzirconium (IV), γ-epoxypropoxypropyltrimethoxyzirconium (IV), 3-isocyanopropyltrimethoxyzirconium (IV), triethoxymono(2,4-pentanedione)zirconium (IV), tri-n-propoxymono(2,4-pentanedione)zirconium (IV), triisopropoxymono(2,4-pentanedione)zirconium (IV), tris(3-methacryloyloxypropyl)methoxyzirconium (IV), and tris(3-acryloyloxypropyl)methoxyzirconium (IV).

[0155] Examples of hafnium-containing compounds include diisopropoxybis(2,4-pentanedione)hafnium (IV), tetrabutoxyhafnium (IV), tetraisopropoxyhafnium (IV), tetraethoxyhafnium (IV), and dichlorobis(cyclopentadienyl)hafnium (IV).

[0156] Of the above, metal alkoxides, metal formates, and metal acetates are preferred, but considering the availability of raw materials, the structure of formula (a-1) is even better.

[0157] [Chemistry 10]

[0158] M(OR 1A )4 (a-1)

[0159] In the formula, M is any one of Ti, Zr, and Hf, and R 1A It is a monovalent organic group with 1 to 20 carbon atoms.

[0160] In the aforementioned equation (a-1), R 1A It is a monovalent organic group having 1 to 20 carbon atoms, preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl, and more preferably isopropyl, n-butyl, or tert-butyl.

[0161] In the synthesis reaction of the metal-containing film forming compound, in addition to the (a) metal compound, a compound which can become a monodentate ligand or a polydentate ligand (hereinafter, (b) ligand forming compound) can be added to the metal-containing film forming compound.

[0162] As the (b) ligand forming compound, in addition to the organic compound derived from the hydroxyl ligand, the carboxyl ligand, the amide ligand, the amine ligand, the ammine ligand, the olefin ligand, and the like exemplified as L in the above general formula (a), an organic compound derived from the ligand from hydroxy acid ester, the ligand from β-diketone, the ligand from β-keto ester, the ligand from α,α-dicarboxylic acid ester, and the like can be exemplified.

[0163] In the metal-containing film forming compound, the content of the ligand having the above ring structure (t) is preferably 10 to 90 mol% of the total of the ligands coordinated to the metal atom, more preferably 20 to 80 mol%, and still more preferably 25 to 75 mol%. The ligand other than the compound having the above ring structure (t), for example, the ligand from the (b) ligand forming compound or the alkoxy group having a carbon number of 1 to 10, is preferably 0 to 90 mol% of the total of the ligands coordinated to the metal atom, and more preferably 20 to 80 mol%.

[0164] Further, in the synthesis reaction of the metal-containing film forming compound, in addition to the (b) ligand forming compound, a (c) silicon-containing compound can be added.

[0165] By substituting the hydrolyzable group of the (a) metal compound with the silicon-containing compound, the stability of the metal-containing film forming compound in the metal-containing film forming composition can be improved.

[0166] As the (c) silicon-containing compound, for example, the following formula (w) structure, and the like can be exemplified.

[0167] [Chemical Formula 11]

[0168]

[0169] In the formula, R A , R B , and R C are any of an organic group having a carbon number of 2 to 30 of a crosslinking group of any of the structures represented by the following general formulae (w-1) to (w-3), and any of an organic group selected from a substituted or unsubstituted alkyl group having a carbon number of 1 to 20, and an aryl group having a carbon number of 6 to 20.

[0170] [Chemical Formula 12]

[0171]

[0172] In the above general formulae (w-1) to (w-3), R s is a hydrogen atom or a monovalent organic group having a carbon number of 1 to 10, q represents 0 or 1, and * represents a bonding portion.

[0173] As the (c) silicon-containing compound, any one of the following compounds is preferable, and trimethylsilanol is more preferable from the viewpoint of productivity.

[0174] [Chemical Formula 13]

[0175]

[0176] In the case where the metal-containing film forming compound contains the ligand having the above ring structure (t) and the ligand from the (c) silicon-containing compound, the content of the ligand having the above ring structure (t) described in the above in the metal-containing film forming compound is preferably 10 to 100 mol% of the total content of the ligands coordinated to the metal atom, more preferably 20 to 80 mol%, and still more preferably 25 to 75 mol%. The ligand from the (c) silicon-containing compound is preferably 10 to 90 mol% of the total content of the ligands coordinated to the metal atom, more preferably 20 to 80 mol%, and still more preferably 25 to 75 mol%. The ligand other than the (b) ligand forming compound and the (c) silicon-containing compound, for example, the ligand from an alkoxy group having a carbon number of 1 to 10 is preferably 0 to 90 mol% of the total content of the ligands coordinated to the metal atom, and more preferably 0 to 75 mol%.

[0177] The synthesis method of the metal-containing film forming compound is not particularly limited, and for example, a metal alkoxide, a metal carboxylate, or a metal acetylacetonate (acac) can be used for the (a) metal compound, and the metal is reacted with the ligand having the above ring structure (t) to obtain the metal-containing film forming compound. The (a) metal compound can be reacted with the ligand having the above ring structure (t) after hydrolysis condensation, or the (a) metal compound can be hydrolysis condensed after being reacted with the ligand having the above ring structure (t). In the case where the control of the hydrolysis condensation is difficult, the (a) metal compound can be reacted with the ligand having the above ring structure (t) in a non-aqueous environment. It is preferable that these be appropriately adjusted in accordance with the properties required for the metal-containing film forming compound and the metal-containing film. In the case where the (c) silicon-containing compound and the compound having the above ring structure (t) are used as the ligand, it is preferable that the (a) metal compound be reacted with the (c) silicon-containing compound, and then the (a) metal compound be reacted with the ligand having the above ring structure (t).

[0178] As the method of using the (a) metal compound to perform the hydrolysis condensation reaction, for example, a method of performing the hydrolysis condensation reaction of the (a) metal compound in a solvent containing water, and the like can be exemplified. At this time, other compounds having a hydrolyzable group can also be added as necessary. Also, as the catalyst of the hydrolysis condensation reaction, an acid such as acetic acid can also be added. As the lower limit of the amount of water used in the above hydrolysis condensation reaction, 0.2 times the mole of the hydrolyzable group possessed by the (a) metal compound or the like is preferable, 1 time the mole is more preferable, and 3 times the mole is further more preferable. As the upper limit of the above amount of water, 20 times the mole is preferable, 15 times the mole is more preferable, and 10 times the mole is further more preferable.

[0179] As the solvent used in the synthesis reaction of the metal-containing film forming compound, there is no particular limitation, and for example, the same solvent as exemplified as the (B) organic solvent described later can be used. As typical solvents and solvent mixtures, those containing an ester, ether, or alcohol functional group, for example, a mixture of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) at 70 / 30 by volume can be used. As examples of other solvents that can be used, butylene glycol monomethyl ether, ethylene glycol monomethyl ether, butylene glycol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, butylene glycol 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-propanol, 4-methyl-2-pentanol, acetone, tetrahydrofuran, toluene, hexane, ethyl acetate, cyclohexanone, methyl amyl ketone, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipentyl ether, isopentyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl acetoacetate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol monoter-butyl ether acetate, γ-butyrolactone, methyl isobutyl ketone, cyclopentyl methyl ether, and the like can be exemplified.

[0180] <metal-containing film forming composition>

[0181] Also, a metal-containing film forming composition according to the present application, which functions as a metal-containing film material used in semiconductor manufacturing, contains the (A) metal-containing film forming compound described above and the (B) organic solvent.

[0182] <(B) organic solvent>

[0183] As the (B) organic solvent that can be used in the metal-containing film forming composition according to the present application, there is no particular limitation as long as it dissolves the (A) metal-containing film forming compound described above, and, if contained, the (C) crosslinking agent, (D) acid generator, (E) surfactant, and other additives described later.

[0184] Specifically, for example, the organic solvent described in paragraphs

[0091] to

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

[0185] The blending amount of the organic solvent is preferably in the range of 200 to 10,000 parts by mass, more preferably 250 to 5,000 parts by mass, with respect to 100 parts by mass of the metal-containing film-forming compound (A).

[0186] <(B1) High-boiling solvent>

[0187] The metal-containing film-forming composition of the present application can contain a (B1) high-boiling solvent in the aforementioned (B) organic solvent.

[0188] That is, it is desirable that the aforementioned (B) organic solvent contain one or more organic solvents having a boiling point of 180°C or higher as the aforementioned (B1) high-boiling solvent.

[0189] For example, 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 ((B1) high-boiling solvent) can be used as the (B) organic solvent.

[0190] As the (B1) high-boiling-point solvent, there is no particular limitation as long as it is a solvent capable of dissolving each component of the metal-containing film-forming composition of the present application, and examples include hydrocarbons, alcohols, ketones, esters, ethers, chlorine-based solvents, and the like. Specific examples include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 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, glycerol, 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 monon-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 monon-propyl ether, dipropylene glycol monon-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monon-propyl ether, tripropylene glycol monon-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-butanediol diacetate, 1,6-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, dibutyl adipate, and the like, and these can be used alone or in combination.

[0191] The (B1) high-boiling-point solvent is preferably a solvent having a boiling point of 180°C to 300°C, and more preferably 200°C to 300°C. If the solvent has such a boiling point, the solvent does not volatilize too quickly during baking (heat treatment), and thus the occurrence of defects due to drying during film formation can be suppressed. Furthermore, if the solvent has such a boiling point, the solvent does not remain in the film even after baking, and thus the film properties such as etching resistance are not adversely affected.

[0192] Further, the blending amount when using the (B1) high-boiling-point solvent is preferably 1 to 30 parts by mass relative to 100 parts by mass of an organic solvent having a boiling point of less than 180°C. If the blending amount is thus, sufficient thermal fluidity can be imparted at the time of baking, and the composition does not remain in the film, so that the film properties such as etching resistance are not deteriorated, and thus the blending amount is preferably 1 to 30 parts by mass.

[0193] [Other Components]

[0194] The aforementioned composition can further contain one or more of (C) a crosslinking agent, (D) an acid generator, and (E) a surfactant.

[0195] Hereinafter, components that can be contained in the composition for forming a metal-containing film of the present application other than the (A) metal-containing film-forming compound and the (B) organic solvent will be described.

[0196] [(C) Crosslinking Agent]

[0197] In the composition for forming a metal-containing film of the present application, a (C) crosslinking agent can be added in order to improve the hardening property and further inhibit intermixing with the resist upper layer film. The crosslinking agent is not particularly limited, and various known crosslinking agents of various systems can be widely used. As an example, a melamine-based crosslinking agent, a glycoluril-based crosslinking agent, a benzoguanamine-based crosslinking agent, a urea-based crosslinking agent, a β-hydroxyalkylamide-based crosslinking agent, an isocyanurate-based crosslinking agent, an aziridine-based crosslinking agent, an oxazoline-based crosslinking agent, an epoxy-based crosslinking agent, and a phenol-based crosslinking agent can be exemplified. The (C) crosslinking agent can be used alone or in combination with two or more, and the amount of the crosslinking agent to be added is preferably 5 to 50 parts by mass, and more preferably 10 to 40 parts by mass, relative to 100 parts by mass of the (A) metal-containing film-forming compound. If the amount of the crosslinking agent to be added is 5 parts by mass or more, sufficient hardening property can be exhibited, and intermixing with the resist upper layer film can be inhibited. On the other hand, if the amount of the crosslinking agent to be added is 50 parts by mass or less, there is no risk of deterioration of dry etching resistance due to a decrease in the proportion of the (A) metal-containing film-forming compound in the composition.

[0198] The melamine-based crosslinking agent can specifically exemplify hexamethoxymethylated melamine, hexabutoxymethylated melamine, an alkoxy- and / or hydroxy-substituted product thereof, and a partial self-condensate thereof.

[0199] The glycoluril-based crosslinking agent can specifically exemplify tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril, an alkoxy- and / or hydroxy-substituted product thereof, and a partial self-condensate thereof.

[0200] The benzoguanamine-based crosslinking agent can specifically exemplify tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, an alkoxy- and / or hydroxy-substituted product thereof, and a partial self-condensate thereof.

[0201] Urea crosslinking agents, specifically, dimethoxymethylated dimethoxy ethylene urea, alkoxyl and / or hydroxyl substituted bodies thereof, and partial self-condensates thereof can be exemplified.

[0202] β-hydroxyalkylamide crosslinking agents, specifically, N,N,N',N'-tetra(2-hydroxyethyl) adipamide can be exemplified.

[0203] Isocyanurate crosslinking agents, specifically, isocyanuric acid triepoxypropyl ester, isocyanuric acid triallyl ester can be exemplified.

[0204] Aziridine crosslinking agents, specifically, 4,4'-bis(vinylimidocarbonylamino)diphenylmethane, 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate] can be exemplified.

[0205] Oxazoline crosslinking agents, specifically, 2,2'-isopropylidenebis(4-benzyl-2-oxazoline), 2,2'-isopropylidenebis(4-phenyl-2-oxazoline), 2,2'-methylenebis(4,5-diphenyl-2-oxazoline), 2,2'-methylenebis(4-phenyl-2-oxazoline), 2,2'-methylenebis(4-tert-butyl-2-oxazoline), 2,2'-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylenebis(2-oxazoline), 2-isopropenyl oxazoline copolymer can be exemplified.

[0206] Epoxy crosslinking agents, specifically, diepoxypropyl ether, ethylene glycol diepoxypropyl ether, 1,4-butanediol diepoxypropyl ether, 1,4-cyclohexanedimethanol diepoxypropyl ether, poly(epoxypropyl methacrylate), trimethylolethane triepoxypropyl ether, trimethylolpropane triepoxypropyl ether, neopentatetrol tetraepoxypropyl ether can be exemplified.

[0207] Phenol crosslinking agents, specifically, a compound represented by the following general formula (10) can be exemplified.

[0208] [Chemical Formula 14]

[0209]

[0210] In the formula, Q is a single bond, or a q-valent hydrocarbon group having a carbon number of 1 to 20. 1 R is a hydrogen atom, or an alkyl group having a carbon number of 1 to 20. 16 R is a hydrogen atom, or an alkyl group having a carbon number of 1 to 20. 1 q is an integer of 1 to 5.

[0211] Q is a single bond, or a q-valent hydrocarbon group having a carbon number of 1 to 20. 1 q is an integer of 1 to 5. 1is an integer of 1 to 5, and is more preferably 2 or 3. Q can be exemplified by, specifically, methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylcumene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, eicosane, and the like, from which q 1 16 is a hydrogen atom or an alkyl group having a carbon number of 1 to 20. The alkyl group having a carbon number of 1 to 20 can be exemplified by, specifically, 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 eicosyl group, and is more preferably a hydrogen atom or a methyl group.

[0212] Examples of the compound represented by the above general formula (10) can be exemplified by, specifically, the following compounds. Among them, from the viewpoint of improving the hardenability of the metal-containing film and the film thickness uniformity, it is more preferable to be a hexamethoxymethylated body of triphenylol methane, triphenylol ethane, 1,1,1-tris(4-hydroxyphenyl)ethane, tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene.

[0213] [Chemical Formula 15]

[0214]

[0215] In the formula, R 16 is the same as the aforementioned formula (10).

[0216] [Chemical Formula 16]

[0217]

[0218] In the formula, R 16 is the same as the aforementioned formula (10).

[0219] <(D) Acid Generator>

[0220] In the composition for forming a metal-containing film of the present application, in order to more promote the hardening reaction of the (A) compound for forming a metal-containing film described above, a (D) acid generator can be added. The acid generator can be either one that generates an acid by thermal decomposition or one that generates an acid by light irradiation, and either one can be added. Specifically, the materials described in

[0061] to

[0085] of Japanese Patent Application Publication No. 2007-199653 can be added, but are not limited to these.

[0221] The acid generator described above can be used alone or in combination with two or more. When the acid generator is added, the amount of addition is preferably 0.05 to 50 parts by mass, and more preferably 0.1 to 10 parts by mass, with respect to 100 parts by mass of the (A) compound for forming a metal-containing film described above.

[0222] <(E) Surfactant>​

[0223] In the metal-containing film formation composition of the present application, in order to improve the coating properties during spin coating, a (E) surfactant can be added. As the surfactant, for example, those described in

[0142] to

[0147] of Japanese Patent Application Publication No. 2009-269953 can be used. When a surfactant is added, the amount of addition is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the above-mentioned (A) metal-containing film formation compound.

[0224] <Method for forming metal-containing film>

[0225] In the present application, a method for forming a metal-containing film that functions as a resist underlayer film or a planarization film for semiconductor manufacturing, which is a multilayer resist film used in photolithography, using the above-mentioned metal-containing film formation composition is provided.

[0226] In the metal-containing film formation method using the metal-containing film formation composition of the present application, the above-mentioned metal-containing film formation composition is coated on a processed substrate using a spin coating method or the like. By using a spin coating method or the like, good filling properties can be obtained. After spin coating, in order to evaporate the solvent and prevent mixing with a resist upper layer film or a resist intermediate film, and in order to promote crosslinking reaction, baking (heat treatment) is performed. The baking is preferably performed at 100°C or higher and 600°C or lower, for 10 to 600 seconds, more preferably at 150°C or higher and 500°C or lower, for 10 to 300 seconds. When the effects on device damage and wafer deformation are considered, the upper limit of the heating temperature in the wafer process of photolithography is preferably 600°C or lower, more preferably 500°C or lower.

[0227] Further, in the metal-containing film formation method using the metal-containing film formation composition of the present application, by coating the metal-containing film formation composition of the present application on a processed substrate using the above-mentioned same spin coating method or the like, and calcining and hardening the above-mentioned metal-containing film formation composition in a gas environment in which the oxygen concentration is 0.1% by volume or higher and 21% by volume or lower, a metal-containing film can also be formed.

[0228] By calcining the metal-containing film formation composition of the present application in such an oxygen gas environment, a sufficiently hardened film can be obtained. As the gas environment during baking, even air is not a problem, but in order to reduce the oxygen, it is preferable to previously seal an inert gas such as N2, Ar, He, etc., because this prevents oxidation of the metal-containing film. In order to prevent oxidation, the oxygen concentration needs to be controlled, and is preferably 1000 ppm or lower, more preferably 100 ppm or lower (on a volume basis). If oxidation of the metal-containing film during baking is prevented, there is no case of increased absorption or decreased etching resistance, so this is preferable.

[0229] <Pattern forming method using metal-containing film forming composition>

[0230] Further, in the pattern forming method using the metal-containing film forming composition, a pattern forming method is provided, which is a method of forming a pattern on a substrate to be processed, characterized by comprising the steps of:

[0231] (I-1) applying the metal-containing film forming composition directly or indirectly on a substrate to be processed, and then performing a heat treatment, thereby forming a metal-containing film;

[0232] (I-2) forming a resist upper layer film directly or indirectly on the metal-containing film using a photoresist material;

[0233] (I-3) performing a pattern exposure on the resist upper layer film, and then developing the resist upper layer film with a developer, thereby forming a pattern on the resist upper layer film;

[0234] (I-4) using the patterned resist upper layer film as a mask, and directly or indirectly transferring the pattern to the metal-containing film by dry etching; and

[0235] (I-5) using the patterned metal-containing film as a mask, and directly or indirectly processing the substrate to be processed, thereby forming a pattern on the substrate to be processed.

[0236] In the pattern forming method of the present application, it is desirable that at least one organic resist lower layer film is interposed between the substrate to be processed and the metal-containing film, and it is more desirable that the resist upper layer film is formed directly on the metal-containing film.

[0237] (3-layer resist process)

[0238] For example, in the pattern forming method using the metal-containing film forming composition, a pattern forming method is provided, which is characterized by: forming an organic resist lower layer film on a substrate to be processed using an organic resist lower layer film material, forming a metal-containing film on the organic resist lower layer film using the metal-containing film forming composition of the present application, forming a resist upper layer film on the metal-containing film using a photoresist material, and performing a pattern exposure on the resist upper layer film, and then developing the resist upper layer film with a developer, thereby forming a pattern on the resist upper layer film, using the patterned resist upper layer film as a mask, and transferring the pattern to the metal-containing film by dry etching, using the pattern-transferred metal-containing film as a mask, and transferring the pattern to the organic resist lower layer film by dry etching, and using the patterned organic resist lower layer film as a mask, and processing the substrate to be processed, thereby forming a pattern on the substrate to be processed.

[0239] A pattern forming method using a 3-layer resist process is shown in Figure 1 . First, an organic resist underlayer film 2 is formed on a substrate to be processed 1 using an organic resist underlayer film material (I-A), and then a metal-containing film 3 is formed on the organic resist underlayer film 2 using the metal-containing film forming composition of the present application (I-B). Next, a resist upper layer film 4 is formed on the metal-containing film 3 using a photoresist material (I-C). Exposure P is performed using a mask 5 (I-D), and after the resist upper layer film 4 and the metal-containing film 3 are exposed (I-E), a resist upper layer film pattern 4a is formed on the resist upper layer film 4 (I-F). The resulting resist upper layer film pattern 4a is used as a mask, and the pattern is transferred to the metal-containing film 3 by dry etching (I-G). After the resist upper layer film pattern 4a is removed, the resulting metal-containing film pattern 3a is used as a mask, and the pattern is transferred to the organic resist underlayer film 2 by dry etching, and an organic resist underlayer film pattern 2a is transferred (I-H). After the metal-containing film pattern 3a is removed, the resulting organic resist underlayer film pattern 2a is used as a mask, and the substrate to be processed 1 is processed to form a pattern 1a on the substrate to be processed (I-I).

[0240] The resist upper layer film of the above 3-layer resist process exhibits etching resistance due to halogen-based gases such as chlorine-based gases and fluorine-based gases, and therefore it is desirable to use an etching gas mainly containing a halogen-based gas for dry etching of the metal-containing film using the resist upper layer film as a mask in the above 3-layer resist process.

[0241] The metal-containing film of the above 3-layer resist process exhibits etching resistance due to oxygen-based gases, and therefore it is desirable to use an etching gas mainly containing an oxygen-based gas for dry etching of the organic resist underlayer film using the metal-containing film as a mask in the above 3-layer resist process.

[0242] The organic resist underlayer film of the above 3-layer resist process exhibits etching resistance due to fluorine-based gases, and therefore it is desirable to use an etching gas mainly containing a fluorine-based gas for dry etching of the substrate to be processed using the organic resist underlayer film as a mask in the above 3-layer resist process.

[0243] As the organic resist underlayer film material that can be used for the above-described organic resist underlayer film, in addition to the 4,4'-(9-fluorenylidene) bisphenol novolak resin (molecular weight 11,000) described in Japanese Patent Application Publication No. 2005-128509, a number of resins, such as a novolak resin, that are known as resist underlayer film materials for 2-layer resist processes, 3-layer resist processes, and the like can be used. Also, in cases where it is desired to improve heat resistance over that of a typical novolak, a polycyclic skeleton, such as a 6,6'-(9-fluorenylidene)-bis(2-naphthol) novolak resin, can also be incorporated, and a polyimide-based resin (for example, Japanese Patent Application Publication No. 2004-153125) can also be further selected.

[0244] The above-described organic resist underlayer film can be formed on a substrate to be processed using a composition solution, and in the same manner as a photoresist composition, using a spin coating method or the like. After the organic underlayer film is formed using a spin coating method or the like, baking is desirably performed in order to evaporate the organic solvent. The baking temperature can desirably be used in a range of 80 to 400°C, and the baking time can desirably be used in a range of 10 to 300 seconds.

[0245] Instead of the above-described organic resist underlayer film, an organic hard mask formed using a CVD method or an ALD method can also be used.

[0246] In the above-described pattern forming method, the resist upper layer film can be either a positive type or a negative type, and the same photoresist composition as that conventionally used can be used. In cases where the resist upper layer film is formed using the above-described photoresist composition, a spin coating method can be used, or a method of forming using evaporation treatment by CVD or ALD can be used.

[0247] In cases where the photoresist composition is formed using a spin coating method, pre-baking is performed after resist coating, and is desirably performed in a range of 60 to 180°C for 10 to 300 seconds. Thereafter, exposure is performed according to a conventional method, and post-exposure baking (PEB) and development are performed, and a resist pattern is obtained. Furthermore, the thickness of the resist upper layer film is not particularly limited, and is desirably 10 to 500 nm, and more desirably 20 to 400 nm.

[0248] As the exposure light, high-energy rays having a wavelength of 300 nm or less can be used, and specifically, excimer lasers of 248 nm, 193 nm, and 157 nm, soft X-rays of 3 to 20 nm, electron beams, X-rays, and the like can be used.

[0249] As for the above-mentioned pattern forming method of the resist upper layer film, pattern formation can be performed using optical lithography with light having a wavelength of 5 nm or more and 300 nm or less, direct drawing by an electron beam, nanoimprint, or a combination thereof, and EUV light is most preferable in the present application.

[0250] Further, it is preferable that the developing method in the above-mentioned pattern forming method be developing by an alkali developer or an organic solvent.

[0251] Next, etching is performed using the obtained resist pattern as a mask. Etching of the metal-containing film in the 3-layer resist process is performed using a chlorine-based or fluorocarbon-based gas with the upper layer resist pattern as a mask. By this, a metal-containing film pattern is formed.

[0252] Next, etching processing of the organic resist lower layer film is performed using the obtained metal-containing film pattern as a mask. The etching processing of the organic resist lower layer film is preferably performed using an etching gas mainly composed of an oxygen-based gas.

[0253] The metal-containing film obtained using the metal-containing film-forming composition of the present application has excellent etching resistance during etching of the organic resist lower layer film.

[0254] Etching of the subsequent processed body can also be performed using a conventional method. For example, if the processed body is SiO2, SiN, a silicon oxide-based low dielectric constant insulating film, or the like, etching is performed using a fluorocarbon-based gas as the main component.

[0255] Further, the processed body (processed substrate) is not particularly limited, and a substrate such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, Al, or the like, on which a processed layer is formed, or the like can be used. As the processed layer, various Low-k films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si, or the like, and a barrier film thereof can be used, and can be formed to a thickness of generally 50 to 10,000 nm, particularly 100 to 5,000 nm. Further, in the case where the processed layer is formed, the substrate and the processed layer can be made of different materials.

[0256] (2-layer resist process)

[0257] Further, the present application, in the pattern forming method using the above-mentioned metal-containing film forming composition in a two-layer resist process, can provide a pattern forming method characterized by forming a metal-containing film on a substrate to be processed using a metal-containing film forming composition, forming a resist upper layer film on the metal-containing film using a photoresist material, and after performing pattern exposure on the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film, using the resist upper layer film pattern as a mask, and transferring the pattern to the metal-containing film by dry etching, using the metal-containing film pattern as a mask, and processing the substrate to be processed by dry etching to form a pattern on the substrate to be processed.

[0258] The metal-containing film obtained using the metal-containing film forming composition of the present application has excellent etching resistance during etching of the substrate to be processed. Therefore, in the above-mentioned two-layer resist process, it is more desirable to perform dry etching of the substrate to be processed using the metal-containing film as a mask using an etching gas mainly composed of a fluorine-based gas.

[0259] (Step of peeling the metal-containing film)

[0260] Further, in the above-mentioned pattern forming method, it is more desirable to include a step of removing the metal-containing film remaining on the pattern of the substrate to be processed with a chemical solution after the step of forming a pattern on the substrate to be processed. In the case where this step is performed after the above-mentioned substrate etching step, the metal-containing film remaining on the upper side of the substrate is removed. Also, this step can be performed on the metal-containing film patterned or not patterned before the above-mentioned substrate etching step.

[0261] A method of wet peeling is shown in Figure 2 A processed body in which an organic resist lower layer film 2, a metal-containing film 3, and a resist upper layer film 4 are formed on a substrate to be processed 1 is first subjected to mask exposure on the resist upper layer film 4. After that, development and rinsing are performed to form a resist upper layer film pattern 4a. After that, the obtained resist upper layer film pattern 4a is used as a mask, and a pattern is transferred to the metal-containing film 3 by dry etching to obtain a metal-containing film pattern 3a. After that, the resist upper layer film pattern 4a is removed, and the obtained metal-containing film pattern 3a is used as a mask, and a pattern is transferred to the organic resist lower layer film 2 by dry etching to obtain an organic resist lower layer film pattern 2a. After that, the metal-containing film pattern 3a is removed by wet peeling.

[0262] The metal-containing film of the present application can be formed without damaging the substrate to be processed, since the metal-containing film can be removed using a chemical solution and by wet processing.

[0263] As the method for removing the metal-containing film, for example, a method in which the metal-containing film is dry-etched, a method in which the metal-containing film is brought into contact with a liquid such as an alkaline solution or an acidic solution can be exemplified.

[0264] As the acid-containing removal solution, if it is an acidic solution containing an acid, there is no particular limitation. From the viewpoint of improving the removal properties of the metal-containing film, it is preferable that the solution contain hydrogen peroxide water and an acid, and more specifically, it is particularly preferable that the solution contain hydrochloric acid and hydrogen peroxide (SC-2 chemical solution), sulfuric acid and hydrogen peroxide (SPM chemical solution), or hydrofluoric acid and hydrogen peroxide (FPM chemical solution).

[0265] As the base-containing removal solution, if it is a basic solution containing a base, there is no particular limitation. As the base, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (hereinafter, also referred to as "TMAH"), tetraethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonene, and the like can be exemplified. Among them, from the viewpoint of avoiding damage to the substrate, ammonia is preferable.

[0266] As the base-containing removal solution, from the viewpoint of improving the removal properties of the metal-containing film, it is preferable that the solution contain a base and water, or a base, hydrogen peroxide water, and water, and more specifically, it is particularly preferable that the solution be a mixed aqueous solution of ammonia and hydrogen peroxide (25% ammonia aqueous solution / 30% hydrogen peroxide aqueous solution / water = 1 / 2 / 40 mixed aqueous solution, 25% ammonia aqueous solution / 30% hydrogen peroxide aqueous solution / water = 1 / 1 / 5 mixed aqueous solution, and the like (SC1)).

[0267] As the method for wet stripping, if it is a method in which the metal-containing film and the stripping chemical solution are brought into contact for a certain period of time under heating, there is no particular limitation, and for example, a method in which a substrate having a metal-containing film is immersed in heated alkaline hydrogen peroxide water, a method in which alkaline hydrogen peroxide water is sprayed in a heated environment, a method in which heated alkaline hydrogen peroxide water is applied, and the like can be exemplified. After these methods, the substrate is subjected to water washing and drying.

[0268] As the lower limit of the temperature at the time of performing the metal-containing film removal step using the stripping chemical solution, 23°C is preferable, 40°C is more preferable, and 50°C is further preferable. As the upper limit of the temperature, 100°C is preferable, and 90°C is more preferable.

[0269] As the lower limit of the impregnation time in the impregnation method, 1 second is preferable, 10 seconds is more preferable, 20 seconds is still more preferable, and 30 seconds is particularly preferable. As the upper limit of the impregnation time, 60 minutes is preferable, 30 minutes is more preferable, 20 minutes is still more preferable, and 10 minutes is particularly preferable from the viewpoint of suppressing the influence on the substrate.

[0270] Examples

[0271] Hereinafter, the present application will be described more specifically by showing synthesis examples, examples, and comparative examples, but the present application is not limited by these.

[0272] [Synthesis Example]

[0273] In the following synthesis examples, the following organic group raw material group G: (G1) to (G12) and silicon-containing organic group raw material group H: (H1) to (H2) are used.

[0274] The organic group raw material group G: (G1) to (G12) is shown below.

[0275] [Chemical 17]

[0276]

[0277] The silicon-containing organic group raw material group H: (H1) to (H2) is shown below.

[0278] [Chemical 18]

[0279]

[0280] The metal source M uses the following metal compounds.

[0281] (M1): Titanium tetraisopropoxide (Sigma-Aldrich Corp, 377996)

[0282] (M2): Zr(OBu)4: Zirconium(IV) tetrabutoxide (80 mass% 1-butanol solution) (Tokyo Chemical Industry Co., Ltd., Z0016)

[0283] (M3): Hf(OBu)4: Hafnium(IV) n-butoxide (Sigma-Aldrich Corp, 667943)

[0284] [Synthesis Example 1] Synthesis of Metal-Containing Film-Forming Compound (A-1)

[0285] Under a nitrogen gas atmosphere, 7.10 g of titanium tetraisopropoxide (Ml) was dissolved in 15.00 g of a PGMEA / PGME (weight ratio 70 / 30) solution, and the reaction temperature was increased to 60°C while stirring. A mixture in which 2.90 g of compound Gl was suspended in 5.50 g of a PGMEA / PGME (weight ratio 70 / 30) solution was added to the above reaction system, the reaction temperature was maintained at 60°C, and stirring was continued for 1 hour. After cooling to room temperature, the resulting reaction solution was filtered with a 0.45 μm PTFE filter, whereby a PGMEA / PGME solution of a metal-containing film- forming compound (A-l) was obtained.

[0286] [Synthesis Examples 2 to 12] Synthesis of metal-containing film-forming compounds (A-2) to (A-9), (R-l) to (R-3)

[0287] Using the above metal source M and the above organic group raw material group G in the amounts shown in Table 1, and otherwise, metal-containing film-forming compounds (A-2) to (A-9), (R-l) to (R-3) shown in Table 1 were obtained by the same reaction conditions as in the above [Synthesis Example 1]. (A-l) is also shown in Table 1.

[0288] [Table 1]

[0289]

[0290] [Synthesis Example 13] Synthesis of metal-containing film-forming compound (A-10)

[0291] Under a nitrogen gas atmosphere, 7.10 g of titanium tetraisopropoxide (Ml) was dissolved in 15.00 g of a PGMEA / PGME (weight ratio 70 / 30) solution, and the reaction temperature was increased to 60°C while stirring. A mixture in which 2.90 g of compound Gl was suspended in 5.50 g of a PGMEA / PGME (weight ratio 70 / 30) solution was added to the above reaction system, the reaction temperature was maintained at 60°C, and stirring was continued for 1 hour. After cooling to room temperature, the resulting reaction solution was filtered with a 0.45 μm PTFE filter, whereby a PGMEA / PGME solution of a metal-containing film- forming compound (A-l) was obtained.

[0292] [Synthesis Example 14] Synthesis of metal-containing film-forming compound (A-11)

[0293] Using the above metal source M, the above organic group raw material group G, and the above silicon-containing organic group raw material group H in the amounts shown in Table 2, except for these, the compound (A-11) shown in Table 2 was obtained by the same reaction conditions as the aforementioned [Synthesis Example 13]. (A-10) is also collectively shown.

[0294] [Table 2]

[0295]

[0296] [Synthesis Example 15] Synthesis of metal-containing film forming compound (A-12)

[0297] Under a nitrogen gas atmosphere, 35.53 g of titanium tetraisopropoxide (M1) was dissolved in 50.00 g of 2-propanol, and a solution of 1.69 g of ion exchange water in 70.0 g of 2-propanol was added dropwise over 2 hours at room temperature while stirring. To the resulting solution, 22.52 g of compound G4 was added, and stirred at room temperature for 30 minutes. This solution was concentrated under reduced pressure at 30°C, and further heated to 60°C, and heated under reduced pressure until no distillate was produced. When no distillate was observed, 100.50 g of a PGMEA / PGME (weight ratio 70 / 30) solution was added, and heated under reduced pressure at 40°C until no IPA was distilled, to obtain a PGMEA / PGME solution of metal-containing film forming compound (A-12).

[0298] [Synthesis Example 16] Synthesis of metal-containing film forming compound (A-13)

[0299] Using the above metal source M, the above organic group raw material group G, except for these, the compound (A-13) shown in Table 3 was obtained by the same reaction conditions as the aforementioned [Synthesis Example 15]. (A-12) is also collectively shown.

[0300] [Table 3]

[0301]

[0302]

[0303] Preparation of metal-containing film forming composition (UDL-1 to 16, comparative UDL-1 to 3)

[0304] The metal-containing film-forming composition was prepared using the above-mentioned metal-containing film-forming compounds (A-1) to (A-13), (D-1) as the acid generator, (XL-1) to (XL-2) as the crosslinking agent, (F1: ethylene glycol dibenzyl ether: boiling point 364°C) as (B1) the high-boiling solvent. After dissolving in an organic solvent at the proportions shown in Table 4, filtration was performed using a fluorine resin filter having a pore size of 0.1 μm, whereby metal-containing film-forming compositions (UDL-1 to 16, Comparative Examples UDL-1 to 3) were each prepared.

[0305] [Chem. 19]

[0306]

[0307] [Table 4]

[0308]

[0309]

[0310] [Etching resistance evaluation (Examples 1-1 to 1-16, Comparative Examples 1-1 to 1-5)]

[0311] The metal-containing film-forming compositions (UDL-1 to 16, and Comparative Examples UDL-1 to 3) were applied to 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 30 nm (film thickness a).

[0312] In Comparative Example 1-4, the following silicon atom-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 30 nm (film thickness a).

[0313] In the case of the silicon atom-containing resist intermediate film material (SOG-1), the polymer represented by the ArF silicon-containing intermediate film polymer (SiPl) and the thermal crosslinking catalyst (CATl) were dissolved in a solvent containing 0.1 mass% of FC-4430 (manufactured by Sumitomo 3M Company) at the proportions shown in Table 5, and filtered using a fluorine resin filter having a pore size of 0.1 μm, whereby the silicon atom-containing resist intermediate film material (SOG-1) was prepared.

[0314] [Table 5]

[0315]

[0316] The structural formulas of the ArF silicon-containing intermediate film polymer (SiPl) and the thermal crosslinking catalyst (CATl) used are shown below.

[0317] [Chem. 20]

[0318]

[0319] In Comparative Examples 1 to 5, the following organic resist underlayer film material (SOC-1) was coated and baked at 350°C for 60 seconds to form a resist underlayer film having a film thickness of 50 nm (film thickness a).

[0320] As for the organic resist underlayer film material (SOC-1), the polymer represented by the organic underlayer film polymer (CP1) was dissolved in a solvent containing 0.1 mass% of FC-4430 (manufactured by Sumitomo 3M Company) at the proportions shown in Table 6, and filtered with a fluorine resin filter having a pore diameter of 0.1 μm, whereby the organic resist underlayer film material (SOC-1) was prepared.

[0321] [Table 6]

[0322]

[0323] The structural formula of the organic underlayer film polymer (CP1) used is shown below.

[0324] [Chemical Formula 21]

[0325]

[0326] Mw = 7,000, Mw / Mn = 3.50

[0327] Next, each etching using a ULVAC etching device CE-300I and CF4 gas and O2 gas under the following conditions was performed, and the film thickness b was measured. From the film thickness etched between the use of each gas and the specified time (film thickness a - film thickness b), the film thickness etched in 1 minute was calculated as the etching rate (nm / min).

[0328] The case where the etching rate for CF4 gas was not more than 20 nm / min was judged as "A (excellent)", the case where it was more than 20 nm / min and not more than 30 nm / min was judged as "B (good)", and the case where it was more than 30 nm / min was judged as "C (poor)".

[0329] The case where the etching rate for O2 gas was not more than 20 nm / min was judged as "A (excellent)", the case where it was more than 20 nm / min and not more than 30 nm / min was judged as "B (good)", and the case where it was more than 30 nm / min was judged as "C (poor)".

[0330] The results are shown in Table 7.

[0331] Dry etching conditions using CF4 gas

[0332] Pressure: 3 Pa

[0333] Antenna RF power: 100 W

[0334] Bias RF power: 15 W

[0335] CF4gas flow rate: 15 seem

[0336] Time: 30 sec

[0337] Dry etching conditions using O2gas

[0338] Pressure: 3 Pa

[0339] Antenna RF power: 300 W

[0340] Bias RF power: 10 W

[0341] O2gas flow rate: 25 seem

[0342] Time: 30 sec

[0343] [Table 7]

[0344]

[0345] As shown in Table 7, it was found that the metal-containing film forming compositions (UDL-1 to 16) of the present application all showed excellent etching resistance to CF4gas and O2gas.

[0346] The results of the examples were superior in etching resistance to CF4gas to SOG-1 used in Comparative Examples 1 to 4, and thus can be said to be 3-layer resist processes suitable for use in combination with an organic resist underlayer film to transfer a resist pattern to a substrate to be processed.

[0347] The results of the examples were superior in etching resistance to O2gas to SOC-1 used in Comparative Example 1-5, and thus can be said to be 2-layer resist processes suitable for use in combination with a photoresist overlayer film to transfer a resist pattern to a substrate to be processed.

[0348] [Coated film wet etching test (Examples 2-1 to 2-16, Comparative Examples 2-1 to 2-4)]

[0349] The metal-containing film-forming composition (UDL-1 to 16 and Comparative Examples UDL-1 to 3) was applied to a silicon substrate, and a hot plate was used to heat at 250°C for 60 seconds to form a metal-containing film having a thickness of 30 nm. The metal-containing film was immersed in an alkaline solution (25% aqueous ammonia solution / 30% hydrogen peroxide aqueous solution / water = 1 / 1 / 5 mixed aqueous solution) at 65°C for 2 minutes, and the remaining film thickness was measured with a JAWOOLLAM M-2000 high-speed spectroscopic ellipsometer to evaluate whether the film thickness changed before and after immersion in the alkaline solution. A change in film thickness of 70% or more was defined as "good", and a change in film thickness of less than 70% was defined as "poor".

[0350] The results are shown in Table 8.

[0351] [Table 8]

[0352]

[0353]

[0354] As shown in Table 8, the metal-containing film-forming composition (UDL-1 to 16) of the present application had good peelability using an alkaline solution, compared with the metal-containing film formed using Comparative Examples UDL-1 to 3, which did not contain a ligand having a specific ring structure (t), and the silicon-containing film formed from SOG-1. It is presumed that the penetration of the stripping solution was improved due to the inclusion of a ligand having a specific ring structure (t). Furthermore, Comparative Example UDL-2 used R-2, which has a ligand from G11. However, G11 has a ring structure (t), but the ligand therefrom is open ring and does not have a ring structure (t).

[0355] [Pattern formation test (Examples 3-1 to 3-16 and Comparative Examples 3-1 to 3-4)]

[0356] On a silicon wafer on which a 100-nm-thick SiO2 film was formed, a SOC film (ODL-306, carbon content 61 atomic %) manufactured by Shokubai Co., Ltd. was used as an organic resist underlayer film, and was applied using spin coating, and a carbon film having a thickness of 50 nm was formed by baking at 350°C for 60 seconds. Subsequently, the above-described metal-containing film-forming composition (UDL-1 to 16 and Comparative Examples UDL-1 to 3) and SOG-1 were applied to the organic resist underlayer film, and a resist intermediate film having a thickness of 30 nm was formed by heating at 250°C or 220°C for 60 seconds using a hot plate.

[0357] Next, the resist material shown in Table 9 was spin-coated on the above metal-containing film, and a prebake at 105°C for 60 seconds using a hot plate was performed to produce a resist film having a thickness of 40 nm. Exposure was performed using an EUV scanning exposure machine NXE3300 (NA 0.33, σ 0.9 / 0.6, dipole illumination, L / S pattern of pitch 36 nm on wafer) manufactured by ASML, and PEB was performed on a hot plate at 100°C for 60 seconds, and development was performed using a 2.38 mass% TMAH aqueous solution for 30 seconds to obtain a pattern having a line size of 22 nm.

[0358] For this line size, length measurement was performed using a length measurement SEM (CG5000) manufactured by Hitachi High-Technologies, and pattern collapse was observed. When no pattern collapse was observed, it was evaluated as good, and when pattern collapse was observed, it was evaluated as poor. Also, the cross-sectional shape was observed using an electron microscope (S-4800) manufactured by Hitachi High-Technologies, and when no tailing shape was observed, it was evaluated as good, and when a clear tailing shape was observed, it was evaluated as poor.

[0359] Also, the exposure amount to obtain a line size of 18 nm was evaluated as sensitivity, and the smaller the exposure amount, the more it was judged to contribute to high sensitivity of the resist upper layer film.

[0360] The results are shown in Table 10.

[0361] [Chemical 22]

[0362]

[0363] [Chemical 23]

[0364]

[0365] Surfactant: FC-4430 manufactured by 3M

[0366] [Table 9]

[0367]

[0368] • Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0369] CyHO (cyclohexanone)

[0370] PGME (propylene glycol monomethyl ether)

[0371] [Table 10]

[0372]

[0373]

[0374] As shown in Table 10, the metal-containing film forming compositions of the present application (UDL-1 to 16) were able to obtain vertical-shaped pattern profiles and no pattern collapse was confirmed when used for forming a 22 nm line width pattern using EUV exposure. It is presumed that the metal-containing film forming compounds of the present application improved adhesion to the resist pattern because of the inclusion of the ligand having the specific ring structure (t). Also, it is presumed that the permeability of the developer was improved, and a resist pattern with high rectangularity was obtained after development. Furthermore, it was found that if the metal-containing film obtained from the metal-containing film forming composition of the present application was used as a resist underlayer film, a resist pattern could be formed with high sensitivity.

[0375] On the other hand, it was found that the metal-containing films formed using metal-containing film forming compounds different from those of the present application (Comparative Examples 3-1 to 3-3) had less collapse suppression effect for fine line patterns than the metal-containing films obtained from the metal-containing film forming compositions of the present application (Examples 3-1 to 3-16). Although no pattern collapse was observed for Comparative Example 3-4 using SOG-1, the resist profile shape showed a tailing shape.

[0376] As described above, the metal-containing film forming compositions containing the metal-containing film forming compounds of the present application have high collapse suppression effect for fine line patterns because of the excellent adhesion to the upper resist, and in addition, are able to form a metal-containing film that can contribute to the improvement of the sensitivity of the upper resist and can be easily removed, and thus have high value in the field of EUV lithography.

[0377] The present specification contains the following aspects.

[0378] [1] A metal-containing film forming compound characterized by comprising:

[0379] The aforementioned metal-containing film forming compound contains at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the aforementioned metal atom via an oxygen atom,

[0380] The aforementioned ligand has a ring structure (t) selected from a ring having a carbon number of 4 or more containing one or more oxygen atoms,

[0381] a ring having a carbon number of 3 or more containing two or more oxygen atoms, and a ring having a carbon number of 3 or more containing one or more oxygen atoms and one or more heteroatoms different from the oxygen atoms.

[0382] [2] The metal-containing film forming compound according to [1], wherein the aforementioned ring structure (t) is a structure containing a ring having a carbon number of 4 or more containing two or more oxygen atoms, or a ring having a carbon number of 4 or more containing one or more oxygen atoms and one or more heteroatoms different from the oxygen atoms.

[0383] [3] The metal-containing film formation compound according to [1] or [2], wherein the aforementioned ring structure (t) is bonded to any one or more of a cyclic hydrocarbon group having 4 to 6 carbons which can also contain a hetero atom, a cyclic hydrocarbon group having 5 to 6 carbons having one or more carbon-carbon double bonds which can also contain a hetero atom, an aromatic ring, or an aromatic heterocycle to form a polycyclic structure.

[0384] [4] The metal-containing film formation compound according to any one of [1] to [3], wherein the aforementioned ring structure (t) is derived from an organic acid containing the aforementioned ring structure (t).

[0385] [5] The metal-containing film formation compound according to [4], wherein the aforementioned organic acid is a carboxylic acid.

[0386] [6] The metal-containing film formation compound according to any one of [1] to [5], wherein the aforementioned ligand is derived from the following structure;

[0387] [Chem. 24]

[0388] Ra(X) n COOH (1)

[0389] In the above formula, Ra is a monovalent organic group containing the aforementioned ring structure (t), X is a group selected from a substituted or unsubstituted alkylene group having 1 to 10 carbons, a substituted or unsubstituted branched alkylene group having 3 to 10 carbons, a substituted or unsubstituted alkylene group having 2 to 10 carbons containing a carbon-carbon double bond, a substituted or unsubstituted branched alkylene group having 3 to 10 carbons containing a carbon-carbon double bond, and n is 0 or 1.

[0390] [7] The metal-containing film formation compound according to any one of [1] to [6], wherein the aforementioned metal-containing film formation compound further comprises a ligand derived from a silicon compound represented by the following general formula (w);

[0391] [Chem. 25]

[0392]

[0393] In the formula, R A , R B , and R C are any of a crosslinking group-containing organic group having 2 to 30 carbons, an organic group selected from a substituted or unsubstituted alkyl group having 1 to 20 carbons, and an aryl group having 6 to 20 carbons;

[0394] [Chem. 26]

[0395]

[0396] In the above general formulae (w-1) to (w-3), R s is a hydrogen atom or a monovalent organic group having a carbon number of 1 to 10, q represents 0 or 1, and * represents a bonding portion.

[0397] [8] The metal-containing film formation compound according to any one of [1] to [7], wherein the metal-containing film formation compound is a metal compound represented by the following formula (a), or a reaction product of a metal-containing compound including any of a hydrolyzate, a condensate, and a hydrolysis condensate of the metal compound represented by the following formula (a) and a compound having the aforementioned ring structure (t);

[0398] [Chem. 27]

[0399] L a MX b (a)

[0400] wherein M is any of Ti, Zr, and Hf; L is a monodentate ligand or a polydentate ligand having a carbon number of 1 to 30, and X is a hydrolyzable group selected from a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, and -NR 1 R 2 R 1 and R 2 are each independently a hydrogen atom or a monovalent organic group having a carbon number of 1 to 20; a + b = 2 to 4, and a and b are integers of 0 to 4.

[0401] [9] The metal-containing film formation compound according to [8], wherein the aforementioned formula (a) is a structure of the following formula (a-1);

[0402] [Chem. 28]

[0403] M(OR 1A )4 (a-1)

[0404] wherein M is any of Ti, Zr, and Hf, and R 1A is a monovalent organic group having a carbon number of 1 to 20.

[0405]

[10] A metal-containing film formation composition which functions as a metal-containing film material used in semiconductor production, characterized by containing: (A) the metal-containing film formation compound according to any one of [1] to [9], and (B) an organic solvent.

[0406]

[11] The metal-containing film formation composition according to

[10] , wherein the aforementioned composition further contains one or more of (C) a crosslinking agent, (D) an acid generator, and (E) a surfactant.

[0407]

[12] The metal-containing film formation composition according to any one of

[10] to

[11] , wherein the aforementioned (B) organic solvent contains one or more organic solvents having a boiling point of 180°C or higher as (Bl) high-boiling-point solvents.

[0408]

[13] A pattern formation method of forming a pattern on a substrate to be processed, characterized by comprising the steps of:

[0409] (I-1) after the metal-containing film formation composition according to any one of

[10] to

[12] is applied directly or indirectly on a substrate to be processed, heat treatment is performed, whereby a metal-containing film is formed;

[0410] (I-2) a resist upper layer film is formed directly or indirectly on the aforementioned metal-containing film using a photoresist material;

[0411] (I-3) after the aforementioned resist upper layer film is subjected to pattern exposure, development is performed with a developer, whereby a pattern is formed on the aforementioned resist upper layer film;

[0412] (I-4) the aforementioned resist upper layer film on which a pattern is formed is used as a mask, and a pattern is transferred to the aforementioned metal-containing film directly or indirectly using dry etching; and

[0413] (I-5) the aforementioned metal-containing film on which a pattern is formed is used as a mask, and the aforementioned substrate to be processed is processed directly or indirectly, whereby a pattern is formed on the aforementioned substrate to be processed.

[0414]

[14] The pattern formation method according to

[13] , wherein at least one organic resist lower layer film is interposed between the aforementioned substrate to be processed and the metal-containing film.

[0415]

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

[13] to

[14] , wherein a resist upper layer film is formed directly on the aforementioned metal-containing film.

[0416]

[16] The pattern formation method according to any one of

[13] to

[15] , wherein after the step of forming a pattern by using the aforementioned metal-containing film as a mask and processing a film directly below the aforementioned metal-containing film, a step of removing the aforementioned metal-containing film with a chemical liquid is included.

[0417]

[17] The pattern formation method according to

[16] , wherein a solution containing hydrogen peroxide water and an acid, or a solution containing a base, hydrogen peroxide water, and water is used as the aforementioned chemical liquid.

[0418] Further, the present application is not limited to the above-described embodiments. The above-described embodiments are examples, and those having substantially the same configuration as the technical idea described in the claims of the present application and exerting the same effects are included in the technical scope of the present application.

[0419] BRIEF DESCRIPTION OF DRAWINGS

[0420] 1: substrate to be processed

[0421] 1a: pattern (pattern formed on the substrate to be processed)

[0422] 2: organic resist underlayer film

[0423] 2a: organic resist underlayer film pattern

[0424] 3: metal-containing film

[0425] 3a: metal-containing film pattern

[0426] 4: resist overlayer film

[0427] 4a: resist overlayer film pattern

[0428] 5: mask

[0429] P: exposure

Claims

1. A metal-containing film forming compound, characterized by: the metal-containing film forming compound comprising at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the metal atom via an oxygen atom, the ligand having a ring structure (t) selected from a ring having a carbon number of 4 or more containing one or more oxygen atoms, a ring having a carbon number of 3 or more containing two or more oxygen atoms, and a ring having a carbon number of 3 or more containing one or more oxygen atoms and one or more heteroatoms different from the oxygen atom. the ring structure (t) is a structure comprising a ring having a carbon number of 4 or more containing two or more oxygen atoms, or a ring having a carbon number of 4 or more containing one or more oxygen atoms and one or more heteroatoms different from the oxygen atom. the ring structure (t) is bonded to any one or more of a cyclic hydrocarbon group having a carbon number of 4 to 6 which can also contain a heteroatom, a cyclic hydrocarbon group having a carbon number of 5 to 6 which has one or more carbon-carbon double bonds and can also contain a heteroatom, an aromatic ring, or an aromatic heterocycle to form a polycyclic structure. the ring structure (t) is derived from an organic acid containing the ring structure (t).

2. The metal-containing film forming compound according to claim 1, wherein, the organic acid is a carboxylic acid.

3. The metal-containing film forming compound according to claim 1, wherein, the ligand is derived from the following structure; 4. The metal-containing film forming compound according to claim 1, wherein, in the above formula, Ra is a monovalent organic group containing the ring structure (t), X is a group selected from a substituted or unsubstituted alkylene group having a carbon number of 1 to 10, a substituted or unsubstituted branched alkylene group having a carbon number of 3 to 10, a substituted or unsubstituted alkylene group having a carbon number of 2 to 10 containing a carbon-carbon double bond, a substituted or unsubstituted branched alkylene group having a carbon number of 3 to 10 containing a carbon-carbon double bond, and n is 0 or 1.

5. The metal-containing film forming compound according to claim 4, wherein, the metal-containing film forming compound further comprises a ligand derived from a silicon compound represented by the following general formula (w); 6. The metal-containing film forming compound according to claim 1, wherein, the metal-containing film forming compound is a reaction product of a metal compound represented by the following formula (a), or a metal-containing compound comprising any one of a hydrolyzate, a condensate, and a hydrolysis condensate of the metal compound represented by the following formula (a), and a compound having the ring structure (t); Ra(X) n COOH (1) the formula (a) is a structure of the following formula (a-1); 7. The metal-containing film forming compound according to claim 1, wherein, the composition further contains one or more of (C) a crosslinking agent, (D) an acid generator, and (E) a surfactant. wherein R A , R B , and R C are organic groups having carbon numbers of 2 to 30 of crosslinking groups of any of structures represented by General Formulae (w-1) to (w-3) below, and are any of organic groups selected from substituted or unsubstituted alkyl groups having carbon numbers of 1 to 20 and aryl groups having carbon numbers of 6 to 20; In the above general formulae (w-1) to (w-3), R s is a hydrogen atom or a monovalent organic group having a carbon number of 1 to 10, q represents 0 or 1, and * represents a bonding portion.

8. The metal-containing film forming compound according to claim 1, wherein, the (B) organic solvent comprises one or more organic solvents having a boiling point of 180°C or higher as (B1) a high-boiling-point solvent. L a MX b (a) wherein M is any of Ti, Zr, and Hf; L is a monodentate ligand or a polydentate ligand having a carbon number of 1 to 30, X is a hydrolyzable group selected from a halogen atom, an alkoxy group, a carboxylate group, an acyloxy group, and -NR 1 R 2 1 and R 2 each independently is a hydrogen atom or a monovalent organic group having a carbon number of 1 to 20; a + b = 2 to 4, a and b are integers of 0 to 4.​ 9. The metal-containing film forming compound according to claim 8, wherein, having the following steps: M(OR 1A )4 (a-1) In the formula, M is any of Ti, Zr, and Hf, R 1A is a monovalent organic group having 1 to 20 carbons.

10. A metal-containing composition for film formation, functioning as a metal-containing film material used in semiconductor manufacturing, characterized in that, (I-1) directly or indirectly applying 11. The metal-containing film forming composition according to claim 10, wherein after the metal-containing film forming composition according to claim 10, heat treatment is performed, whereby a metal-containing film is formed; 12. The metal-containing film forming composition according to claim 10, wherein (I-2) directly or indirectly forming a resist upper layer film on the metal-containing film using a photoresist material; 13. A pattern forming method, characterized in that, (I-3) after the resist upper layer film is subjected to pattern exposure, development is performed with a developer, whereby a pattern is formed in the resist upper layer film; (I-4) using the resist upper layer film having the pattern formed therein as a mask, a pattern is transferred to the metal-containing film directly or indirectly by dry etching; and (I-5) removing the resist upper layer film having the pattern formed therein. ​ ​ ​ (I-5) using the patterned metal-containing film as a mask and directly or indirectly processing the processed substrate to form a pattern in the processed substrate.

14. The pattern forming process according to claim 13, wherein At least one organic resist underlayer film is included between the processed substrate and the metal-containing film.

15. The pattern forming process according to one of claims 13, wherein An resist overlayer film is formed directly on the metal-containing film.

16. The pattern forming process according to claim 13, wherein After the step of using the metal-containing film as a mask and processing a film directly under the metal-containing film to form a pattern, a step of removing the metal-containing film with a chemical liquid is included.

17. The pattern forming method according to claim 16, which uses a solution containing hydrogen peroxide water and an acid, or a solution containing an alkali, hydrogen peroxide water, and water as the chemical liquid.

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