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 purpose of the present invention is to provide: a compound for forming a metal-containing film, said compound being capable of providing a fine patterning process in a semiconductor device manufacturing step, in which a good pattern shape can be obtained, and in which a pattern can be formed in a fine patterning process; a composition for forming a metal-containing film using the compound; and a pattern forming method using the composition. The resist intermediate film has high adhesion to the resist upper layer film and suppresses the collapse of the fine pattern. [Solution] A compound for forming a metal-containing film, which is (A) a compound for forming a metal-containing film, and which is characterized in that: the (A) compound for forming a metal-containing film contains at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand that is coordinated to the metal atom; at least one of the ligands is derived from an organic sulfonic acid compound represented by formula (s).

Description

Technical Field

[0001] The present invention relates to a metal-containing film forming compound used for fine patterning in a multilayer resist method during semiconductor device manufacturing, a metal-containing film forming composition using the compound, and a patterning method using the material. Background Technology

[0002] With the increasing integration and speed of LSI (Lithium-ion Sensor), the miniaturization of pattern sizes is rapidly advancing. Photolithography, while achieving this miniaturization, utilizes appropriately selected short wavelengths of light sources and corresponding resist compositions to form fine patterns. At the heart of this process is the positive photoresist composition used in a single layer. This single-layer positive photoresist composition employs a framework within the resist resin that exhibits etching resistance to chlorine- or fluorine-based gas plasmas during dry etching, and includes a switching mechanism that dissolves the exposed area to form a pattern. The remaining resist pattern then serves as an etching mask for dry etching of the substrate.

[0003] However, directly reducing the thickness of the photoresist film, i.e., further shrinking the pattern width, will decrease the resolution of the photoresist film. Furthermore, if the photoresist film is to be developed using a developer, the aspect ratio will become too large, resulting in pattern corruption. Therefore, with the miniaturization of the pattern, the photoresist film becomes thinner.

[0004] On the other hand, in the processing of substrates, a patterned photoresist film is typically used as an etching mask, and dry etching is employed to process the substrate. However, in reality, there is no dry etching method that can achieve complete etch selectivity between the photoresist film and the substrate. Therefore, during substrate processing, the photoresist film can be damaged and break down, making it impossible to correctly transfer the resist pattern onto the substrate. Consequently, with the miniaturization of patterns, higher dry etching resistance is required for the resist composition. However, to improve resolution, the resin used in the photoresist composition needs to have low light absorption at the exposure wavelength. Therefore, as the exposure light becomes shorter wavelengths such as i-rays, KrF, and ArF, the resins also change to phenolic varnish resins, polyhydroxystyrene, and resins with aliphatic polycyclic skeletons. However, in reality, the etching rate in the dry etching conditions during substrate processing is faster, and the most recent photoresist compositions with high resolution tend to have weaker etching resistance.

[0005] Therefore, it has become necessary to use thinner photoresist films with weaker etching resistance to dry etch the substrate, and ensuring the quality of materials and processing in this step is of paramount importance.

[0006] One approach to address this problem is the multilayer photoresist method. This method involves placing an intermediate photoresist film with a different etching selectivity than the photoresist film (i.e., the top photoresist film) between the top photoresist film and the substrate being processed. After a pattern is obtained on the top photoresist film, the pattern is used as a dry etching mask to transfer the pattern onto the intermediate photoresist film via dry etching. Then, the intermediate photoresist film is used as a dry etching mask to transfer the pattern onto the substrate being processed via dry etching.

[0007] One type of multilayer photoresist method is the three-layer photoresist method, which utilizes common photoresist compositions used in single-layer photoresist methods. In this three-layer photoresist method, for example, an organic film obtained using phenolic resin or similar materials is formed on the substrate as the lower photoresist layer, a silicon-containing photoresist intermediate film is formed on top of it as the middle photoresist layer, and a conventional organic photoresist film is formed on top of it as the upper photoresist layer. During dry etching using fluorine-based gas plasma, the organic upper photoresist layer exhibits good etch selectivity towards the silicon-containing photoresist intermediate film; therefore, the pattern on the upper photoresist layer can be transferred to the silicon-containing photoresist intermediate film via dry etching using fluorine-based gas plasma. This method allows for the transfer of patterns onto a silicon-containing photoresist intermediate film (photoresist intermediate film) even when using photoresist compositions that are difficult to form with sufficient film thickness for direct processing of the substrate, or photoresist compositions that lack sufficient dry etching resistance to the substrate. Then, by performing dry etching using oxygen-based or hydrogen-based gas plasma, a pattern can be obtained from an organic film (photoresist underlayer film) using a phenolic varnish resin or similar material that exhibits sufficient dry etching resistance to the substrate. Several photoresist underlayer films, such as those described in Patent Document 1, are known.

[0008] The silicon-containing photoresist interlayer used in the three-layer photoresist method described above can be a silicon-containing inorganic film obtained by CVD, such as a SiO2 film (e.g., Patent Document 2), a SiON film (e.g., Patent Document 3), an SOG (spin-coated glass) film obtained by spin coating (e.g., Patent Document 4, Non-Patent Document 1), a cross-linked silsesquioxane film (e.g., Patent Document 5), or a polysilane film (e.g., Patent Document 6). Among these, while SiO2 and SiON films offer high performance as dry etching masks for dry etching the underlying organic film, film formation requires specialized equipment. In contrast, SOG films, cross-linked silsesquioxane films, and polysilane films can be formed simply by spin coating and heating, resulting in high processing efficiency.

[0009] The silicon-containing films used in such multilayer resist methods have some problems. For example, when forming resist patterns using photolithography, the exposure light is reflected from the substrate and interferes with the incident light, causing the well-known problem of standing waves. To obtain fine patterns without edge roughness in the resist film using state-of-the-art ArF immersion / high NA exposure conditions, the intermediate film needs anti-reflection properties. Furthermore, as in the aforementioned state-of-the-art semiconductor processing, to further develop the thinning of photoresists, the intermediate film also needs to be thinned. In next-generation exposure processes, anti-reflection effects need to be provided at film thicknesses below 30 nm. Also, to improve the etch selectivity ratio between the intermediate film and the underlying film, a lower dry etching rate against commonly used oxygen plasma is preferable when processing the underlying resist film. Considering the thinning process, the intermediate film needs improved dry etching resistance.

[0010] To meet the requirements for such anti-reflective properties and dry etching characteristics, Ti- and Zr-containing metal hard mask films have gained attention as a replacement for conventional silicon-containing films. TiO2 and ZrO2 are known as high-refractive-index materials, and incorporating them into the film can improve anti-reflective performance under high nano-exposure conditions. Furthermore, the inclusion of metal-oxygen bonds promises excellent dry etching resistance to oxygen.

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

[0012] On the other hand, when such a hard metal mask film is used directly beneath the top layer of the photoresist film, 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 much higher surface energy (or a smaller water contact angle) compared to the photoresist used subsequently. This surface energy mismatch can cause poor adhesion between the hard metal mask film and the photoresist used later, leading to pattern collapse.

[0013] To suppress photoresist pattern collapse on a metal hard mask film, surface modification of the metal hard mask film is required. For example, Patent Document 7 reports a metal hard mask containing a surface-modified organic polymer. It is reported that by utilizing the difference in free energy between the organic polymer and the metal compound, the organic polymer is unevenly distributed on the surface, thereby improving adhesion to the photoresist pattern. To suppress pattern collapse, an organic polymer containing a surface-treated portion selected from hydroxyl groups, protected hydroxyl groups, protected carboxyl groups, and mixtures thereof is used. However, given the current pursuit of forming finer patterns, the pattern collapse suppression performance of these materials is not considered sufficient. Furthermore, the inclusion of organic polymers poses a risk of deterioration in resistance to dry etching with oxygen; therefore, there is a need to develop metal-containing film-forming compounds with excellent adhesion to the upper layer of the photoresist film.

[0014] Recently, the interaction between the interface of the upper resist film and the lower film directly beneath the upper resist film in fine patterns has also affected the sensitivity of the resist, the shape of the pattern (rectangularity and residue at the spacing), etc. Considering these points, the performance of the lower film directly beneath the upper resist film also needs to be improved (Non-Patent Literature 2).

[0015] Existing technical documents

[0016] Patent documents

[0017] [Patent Document 1] Japanese Patent Application Publication No. 2004-205685

[0018] [Patent Document 2] Japanese Patent Application Publication No. 7-183194

[0019] [Patent Document 3] Japanese Patent Application Publication No. 7-181688

[0020] [Patent Document 4] Japanese Patent Application Publication No. 5-291208

[0021] [Patent Document 5] Japanese Patent Publication No. 2005-520354

[0022] [Patent Document 6] Japanese Patent Application Publication No. 11-60735

[0023] [Patent Document 7] Japanese Patent Publication 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 of the Invention

[0027] [The problem that the invention aims to solve]

[0028] The present invention is based on the above circumstances and aims to provide a metal-containing film forming compound, a metal-containing film forming composition using the compound, and a pattern forming method using the composition. The metal-containing film forming compound provides a resist intermediate film that, in the micropatterning process during semiconductor device manufacturing, yields a good pattern shape, has high adhesion to the upper resist film, and suppresses the collapse of the micropattern.

[0029] [Methods for solving the problem]

[0030] To address the aforementioned issues, the present invention provides a metal-containing compound for film formation, namely (A) a metal-containing compound for film formation, characterized in that:

[0031] The (A) metal-containing film-forming compound comprises at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the metal atom.

[0032] At least one of the ligands is an organic sulfonic acid compound represented by the following formula (s).

[0033] [Chemistry 1]

[0034]

[0035] In the formula, R0 represents a monovalent organic group containing one or more of an unsaturated hydrocarbon group excluding an aromatic ring and an alkoxy group, having 1 to 30 carbon atoms.

[0036] If the compound is a metal-containing film-forming compound, its use in metal-containing film-forming compositions can improve adhesion to the upper layer of the resist film, while the shape of the resist pattern after exposure and development is rectangular. This allows for substrate processing using fine patterns.

[0037] The R0 preferably contains one or more monovalent organic groups with 1 to 30 carbon atoms selected from vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, and alkoxy.

[0038] If the compound is a metal-containing film-forming compound, its use in metal-containing film-forming compositions can improve adhesion to the upper layer of the resist film, while the shape of the resist pattern after exposure and development is rectangular. This allows for substrate processing using fine patterns.

[0039] The R0 preferably contains one or more alkyl groups with 2 to 30 carbon atoms selected from vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, and alkoxy groups, or aryl groups with 7 to 30 carbon atoms.

[0040] If the compound is a metal-containing film-forming compound, its use in metal-containing film-forming compositions can improve adhesion to the upper layer of the resist film, while the shape of the resist pattern after exposure and development is rectangular. This allows for substrate processing using fine patterns.

[0041] The R0 preferably contains an aryl group with 7 to 30 carbons selected from one or more functional groups selected from vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, and alkoxy.

[0042] If the metal-containing film-forming compound is used, the heat resistance will be improved. When used in metal-containing film-forming compositions, the adhesion to the upper layer of the resist film can be further improved, and the shape of the resist pattern after exposure and development is rectangular. This allows for substrate processing using fine patterns.

[0043] The metal-containing film-forming compound (A) preferably also contains ligands from silicon compounds represented by the following general formula (w).

[0044] [Chemistry 2]

[0045]

[0046] In the formula, R A R B and R C It is any organic group selected from the following general formulas (w-1) to (w-3) having any crosslinking group having 2 to 30 carbons, substituted or unsubstituted alkyl groups having 1 to 20 carbons, and aryl groups having 6 to 20 carbons.

[0047] [Chemistry 3]

[0048]

[0049] In general formulas (w-1) to (w-3), R s It is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bonded part.

[0050] The aforementioned compounds can enhance the stability of the aforementioned metal compounds in solution by also including ligands from silicon compounds represented by the above general formula (w).

[0051] The reaction product of the metal-containing film formation of (A) is preferably a metal compound represented by formula (a), or a metal compound containing any of the following: hydrolysate, condensate, and hydrolysis-condensate of the metal compound represented by formula (a), and a compound containing the structure represented by formula (s).

[0052] [Chemistry 4]

[0053] L a MX b (a)

[0054] In the formula, M is any of Ti, Zr, and Hf, L is a monodentate or polydentate ligand with 1 to 30 carbon atoms, and X is selected from halogen atoms, alkoxy groups, carboxylic acid groups, acyloxy groups, and -NR. 1 R 2 Hydrolyzable groups, R 1 and R 2Each is an independent hydrogen atom or a monovalent organic group with 1 to 20 carbon atoms, a + b = 2 to 4, where a and b are integers from 0 to 4.

[0055] By using such metal compounds, metal-containing films with better resistance to dry etching by fluorine and oxygen can be formed.

[0056] The structure of the aforementioned equation (a) is better than that of the following equation (a-1).

[0057] [Chemistry 5]

[0058] M(OR 1A )4 (a-1)

[0059] 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.

[0060] If it is a metal compound with such a structure, then it is ideal from the perspective of productivity and the availability of raw materials.

[0061] Furthermore, the present invention provides a metal-containing film forming composition that functions as a metal-containing film material used in semiconductor manufacturing, and contains the aforementioned (A) metal-containing film forming compound and (B) organic solvent.

[0062] If such a metal-containing composition is used for film formation, a metal-containing film can be formed that has excellent dry etching resistance compared to conventional resist underlayer film materials, as well as excellent adhesion to the resist overlayer film and wet peeling properties.

[0063] The aforementioned composition preferably further contains one or more of (C) a crosslinking agent, (D) an acid generating agent, and (E) a surfactant.

[0064] If the composition for forming a metal-containing film contains the above-mentioned additives, it will become a composition for forming a metal-containing film with better coating properties, dry etching resistance, and filling and / or planarization characteristics.

[0065] It is preferable that the aforementioned organic solvent (B) contains one or more organic solvents that have a boiling point of 180°C or higher, which are also high-boiling point solvents (B1).

[0066] The addition of (B1) a high-boiling-point solvent to the above-mentioned metal-containing film-forming compound provides flowability, thereby suppressing the generation of coating defects in the metal-containing film-forming composition due to drying.

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

[0068] (I-1) After directly or indirectly coating the aforementioned metal-containing film-forming composition onto the substrate to be processed, a heat treatment is performed to form a metal-containing film.

[0069] (I-2) A photoresist material is used directly or indirectly on the aforementioned metal-containing film to form a photoresist top layer film.

[0070] (I-3) After exposing the aforementioned upper resist film to a pattern, develop it with a developer to form a pattern on the aforementioned upper resist film.

[0071] (I-4) Using the aforementioned patterned resist film as a mask, the pattern is directly or indirectly transferred to the aforementioned metal-containing film by dry etching.

[0072] (I-5) Using the aforementioned patterned metal-containing film as a mask, the aforementioned substrate is directly or indirectly processed to form a pattern on the aforementioned substrate.

[0073] If such a pattern formation method is used, the collapse of fine patterns that have high adhesion to the upper layer of the resist film can be suppressed.

[0074] Furthermore, in the pattern forming method of the present invention, at least one organic resist lower layer film may be present between the aforementioned processed substrate and the aforementioned metal-containing film.

[0075] If such a pattern forming method is used, the pattern can be transferred onto the substrate being processed with high precision.

[0076] Furthermore, in the pattern forming method of the present invention, it is preferable to directly form the aforementioned upper layer film of the resist on the aforementioned metal-containing film.

[0077] The metal-containing film formed using the metal-containing film-forming compound of the present invention exhibits excellent adhesion to the upper resist film, thus obtaining a resist upper film pattern with high rectangularity.

[0078] Furthermore, in the pattern forming method of the present invention, it is preferable to include a step of removing the aforementioned metal-containing film using a chemical solution after the step of using the aforementioned metal-containing film as a mask and processing the film directly beneath the aforementioned metal-containing film to form a pattern.

[0079] Such a pattern forming method will suppress damage to the substrate and make it easy to remove the metal-containing film, thus forming a rectangular pattern with excellent cross-sectional shape.

[0080] The aforementioned chemical solution is preferably a liquid containing hydrogen peroxide and acid, or a liquid containing alkali, hydrogen peroxide and water.

[0081] If the chemical solution is such, the metal-containing film formed using the metal-containing film-forming compound of the present invention can be easily removed.

[0082] [The effects of the invention]

[0083] As explained above, the metal-containing film-forming compound of the present invention has at least one ligand from the organic sulfonic acid compound represented by formula (s) above. Therefore, when used to form a metal-containing film, it can improve the adhesion to the upper layer of the resist film, and the shape of the resist pattern after exposure and development will be rectangular. Therefore, the composition for forming a metal-containing film using this compound and the pattern-forming method using this composition are applicable to pattern-forming methods such as multilayer resist processing. Attached Figure Description

[0084] [ Figure 1 ] Figure 1 (IA) to (II) are schematic diagrams of an example of the pattern forming method of the present invention (3-layer resist treatment).

[0085] [ Figure 2 ] Figure 2 This is a schematic diagram of an example of the pattern formation method using wet stripping (3-layer resist treatment) of the present invention. Detailed Implementation

[0086] As described above, the present invention provides a metal-containing film-forming compound having a high adhesion to the upper layer of the resist film and suppressing the collapse of fine patterns, a metal-containing film-forming composition using the compound, and a pattern-forming method using the composition.

[0087] The resist underlayer film formed using conventional metal-containing film-forming compounds has a much higher surface energy (or a smaller water contact angle) compared to the photoresist used subsequently. This surface energy mismatch can lead to poor adhesion between the metal-containing film and the subsequent photoresist, resulting in pattern collapse. Furthermore, when organic polymers are mixed in as surface modifiers, the dry etching resistance during the processing of the organic underlayer film becomes insufficient, potentially causing poor pattern transfer.

[0088] The inventors of this application have repeatedly and thoroughly explored the above-mentioned problems and found that the above-mentioned problems can be solved and the present invention can be completed by using a metal-containing film-forming compound containing a ligand with a specific structure, a metal-containing film-forming composition using the compound, and a pattern-forming method using the composition.

[0089] That is, the present invention is a metal-containing film-forming compound, specifically (A) a metal-containing film-forming compound, characterized in that:

[0090] The (A) metal-containing film-forming compound comprises at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the metal atom.

[0091] At least one of the ligands is an organic sulfonic acid compound represented by the following formula (s).

[0092] [Chemistry 6]

[0093]

[0094] In the formula, R0 represents a monovalent organic group containing one or more of an unsaturated hydrocarbon group excluding an aromatic ring and an alkoxy group, having 1 to 30 carbon atoms.

[0095] Furthermore, the present invention is a metal-containing film forming composition that functions as a metal-containing film material used in semiconductor manufacturing, and contains the (A) metal-containing film forming compound and (B) organic solvent described above.

[0096] The present invention will now be described in detail, but the invention is not limited thereto.

[0097] <Compounds for metal-containing film formation>

[0098] A metal-containing film-forming compound, (A) a metal-containing film-forming compound, characterized in that:

[0099] The (A) metal-containing film-forming compound comprises at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the metal atom.

[0100] At least one of the ligands is an organic sulfonic acid compound represented by the following formula (s).

[0101] If it is such a metal compound, when using a metal-containing film-forming composition, it has excellent dry etching resistance compared to conventional resist underlayer film materials, and can form a metal-containing film with excellent adhesion to the resist overlayer film.

[0102] In the above formula (s), R0 preferably contains one or more monovalent organic groups having 1 to 30 carbon atoms, selected from vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, and alkoxy. It is even more preferable to contain one or more alkyl groups having 2 to 30 carbon atoms or aryl groups having 7 to 30 carbon atoms, selected from vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, and alkoxy.

[0103] By including such functional groups, cross-linking reactions between ligands can occur, thereby forming a metal-containing film with excellent adhesion to the upper layer of the resist film.

[0104] The aforementioned alkyl and aryl groups may also have functional groups other than those selected from vinyl, allyl, allyloxy, ethynyl, propynyl, propynyloxy, and alkoxy groups. For example, the hydrogen atoms on the aforementioned alkyl and aryl groups may also be replaced by halogen atoms, alkyl halides, etc.

[0105] Examples of compounds derived from the aforementioned ligands can be illustrated by the following structures.

[0106] [Chemistry 7]

[0107]

[0108] In the above structures, hydrogen atoms may also be substituted by substituted or unsubstituted alkyl groups with 1 to 10 carbon atoms, substituted or unsubstituted aryl groups with 6 to 20 carbon atoms, substituted or unsubstituted organic groups with 2 to 10 carbon atoms containing unsaturated hydrocarbons (excluding aromatic rings), halogen atoms, or halogenated alkyl groups. a It represents an alkyl group with 1 to 10 carbon atoms, substituted or unsubstituted, or an aryl group with 1 to 10 carbon atoms, where p is 1 to 5 and n is 1 to 10.

[0109] In the above formula (s), it is preferable that R0 contains an aryl group with 7 to 30 carbons selected from any one of the functional groups of vinyl, allyl, allyloxy, ethynyl, propynyl, propynyloxy, and alkoxy.

[0110] It is believed that such metal-containing film-forming compounds exhibit improved heat resistance and further promote cross-linking reactions between ligands. When used in metal-containing film-forming compositions, their adhesion to the resist overlayer is further enhanced, and the resist pattern after exposure and development becomes rectangular. This allows for substrate processing using fine patterns.

[0111] The aforementioned organic sulfonic acid compound is preferably represented by the structure of formula (s-1).

[0112] [Chemistry 8]

[0113]

[0114] In the above structure, Z is an organic group containing one or more of the following: vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, and alkoxy, with 1 to 10 carbon atoms; R... z It is a monovalent organic group or halogen atom with 1 to 10 carbon atoms, where m is 0 or 1, s is 1 or 2, and r is 0 to 2.

[0115] In the above equation (s-1), R zIt is preferred to contain any of the following: substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted aryl groups having 6 to 10 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 10 carbon atoms, substituted or unsubstituted organic groups having 2 to 10 carbon atoms in unsaturated hydrocarbons (excluding aromatic rings), halogenated alkyl groups having 1 to 10 carbon atoms, and halogen atoms.

[0116] From the perspective of dry etching resistance, it is better for m to be 0, s to be 1, and r to be 0 or 1 in the above formula (s-1).

[0117] The metal-containing film-forming compound mentioned above (A) is preferably a metal compound represented by formula (a), or a reaction product of a metal compound containing any of the following: hydrolysate, condensate, and hydrolysate-condensate of the metal compound represented by formula (a) and a compound containing the structure represented by formula (s) mentioned above.

[0118] [Chemistry 9]

[0119] L a MX b (a)

[0120] In the formula, M is any of Ti, Zr, and Hf, L is a monodentate or polydentate ligand with 1 to 30 carbon atoms, and X is selected from halogen atoms, alkoxy groups, carboxylic acid groups, acyloxy groups, and -NR. 1 R 2 Hydrolyzable groups, R 1 and R 2 Each is an independent hydrogen atom or a monovalent organic group with 1 to 20 carbon atoms, a + b = 2 to 4, where a and b are integers from 0 to 4.

[0121] If it is such a metal-containing film-forming compound, when used in a metal-containing film-forming composition, it can form a metal-containing film with excellent resistance to dry etching by fluorine gas and oxygen.

[0122] [(a) Metal-containing compounds]

[0123] (Hydrolytic groups)

[0124] The hydrolytic group X in formula (a) above can be, for example, a halogen atom, an alkoxy group, a carboxylic acid group, an acyloxy group, and -NR. 1 R 2 R 1 and R 2 It is preferable that each of them is an independent hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0125] The aforementioned halogen atoms include, for example, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0126] Examples of the aforementioned alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, etc.

[0127] Examples of carboxylic acid groups mentioned above include acetic acid, propionic acid, butyric acid, hexanoic acid, and octanoic acid.

[0128] Examples of the aforementioned acyloxy groups include acetoxy, ethynyloxy, propionyloxy, butyryloxy, tert-butyryloxy, tert-valeryloxy, n-hexylcarbonyloxy, and n-octylcarbonyloxy.

[0129] The above-NR 1 R 2 Examples include unsubstituted amino groups, methylamino groups, dimethylamino groups, diethylamino groups, dipropylamino groups, etc.

[0130] The hydrolyzable group X is preferably an alkoxy group, and even more preferably a propoxy, butoxy, or tert-butoxy group.

[0131] (Monodentate ligand)

[0132] Examples of monodentate ligands include, for instance, hydroxyl ligands, carboxyl ligands, amide ligands, amine ligands, ammonia ligands, and olefin ligands.

[0133] Examples of the aforementioned amide ligands include, for instance, unsubstituted amide ligands (NH2), methylamide ligands (NHMe), dimethylamide ligands (NMe2), diethylamide ligands (NEt2), and dipropylamide ligands (NPr2).

[0134] The aforementioned amine ligands include, for example, pyridine, trimethylamine ligands, piperidine ligands, etc.

[0135] Olefin ligands, for example, include chain olefins such as ethylene and propylene, and cyclic olefins such as cyclopentene, cyclohexene, and norcamphene.

[0136] (Multidentate ligand)

[0137] The aforementioned polydentate ligands L, for example, include ligands derived from hydroxy acid esters, ligands derived from β-diketones, ligands derived from β-keto esters, ligands derived from α,α-dicarboxylic acid esters, hydrocarbons having π bonds, diphosphine, etc.

[0138] Examples of the aforementioned hydroxy esters include glycolate, lactate, 2-hydroxycyclohexane-1-carboxylic acid ester, and salicylate.

[0139] Examples of the aforementioned β-diketones include acetoacetate, α-alkyl-substituted acetoacetate, β-ketovalerate, benzoylacetate, and 1,3-propanone dicarboxylate.

[0140] Examples of the aforementioned α,α-dicarboxylic acid esters include malonate diesters, α-alkyl-substituted malonate diesters, α-cycloalkyl-substituted malonate diesters, and α-aryl-substituted malonate diesters.

[0141] The hydrocarbons with π bonds mentioned above include, for example, chain dienes such as butadiene and isoprene, cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene, norcampadiene and other cyclic dienes, benzene, toluene, xylene, hexamethylbenzene, naphthalene, indene and other aromatic hydrocarbons.

[0142] Examples of the aforementioned diphosphines include 1,1-bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl, and 1,1'-bis(diphenylphosphino)ferrocene.

[0143] In the above general formula (a), a + b = 2 to 4, and a and b are integers from 0 to 4. It is preferable for a to be 0 to 4, and 2 or 4 is even better. It is preferable for b to be 0 to 4, and 0, 2 or 4 is even better. By setting a and b to the above ranges, the stability of the metal-containing film-forming compound (A) can be improved.

[0144] A preferred example of a metal-containing film-forming compound represented by formula (a) is shown below.

[0145] Examples of titanium-containing compounds include diisopropoxybis(2,4-pentanedione)titanium (IV), tetra-n-butoxytitanium (IV), tetra-n-propoxytitanium (IV), tetraisopropoxytitanium (IV), tri-n-butoxytitanium monostearate (IV), butoxytitanium (IV) oligomers, 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).

[0146] Examples of zirconium-containing compounds include dibutoxybis(ethyl acetoacetic acid) zirconium (IV), di-n-butoxybis(2,4-pentanedione) zirconium (IV), tetra-n-butoxy zirconium (IV), tetra-n-propoxy zirconium (IV), tetra-isopropoxy zirconium (IV), aminopropyltriethoxy zirconium (IV), 2-(3,4-epoxycyclohexyl)ethyltrimethoxy zirconium (IV), γ-epoxypropoxypropyltrimethoxy zirconium (IV), 3-isocyanopropyltrimethoxy zirconium (IV), triethoxymono(2,4-pentanedione) zirconium (IV), tri-n-propoxymono(2,4-pentanedione) zirconium (IV), triisopropoxymono(2,4-pentanedione) zirconium (IV), tris(3-methacryloyloxypropyl)methoxy zirconium (IV), and tris(3-acryloyloxypropyl)methoxy zirconium (IV).

[0147] Examples of hafnium-containing compounds include diisopropoxybis(2,4-pentanedione)hafnium (IV), tetrabutoxyhafnium (IV), tetraisopropoxyhafnium (IV), tetraethoxyhafnium (IV), and dichlorobis(cyclopentadienyl)hafnium (IV).

[0148] Of the above, metal alkoxides, metal carboxylates, and metal acetates are preferred. Considering the availability of raw materials, the structure of formula (a-1) is even better.

[0149] [Chemistry 10]

[0150] M(OR 1A )4 (a-1)

[0151] 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.

[0152] In the aforementioned equation (a-1), R 1A It is a monovalent organic group with 1 to 20 carbon atoms, preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, or tert-butyl, with isopropyl, n-butyl, or tert-butyl being even more preferred.

[0153] (A) In the synthesis reaction of metal-containing film-forming compounds, in addition to (a) metal compounds, compounds that can become monodentate or polydentate ligands in the metal-containing film-forming compounds may also be added (hereinafter referred to as (b) ligand-forming compounds).

[0154] The ligand-forming compounds mentioned in (b) above include, for example, organic compounds derived from hydroxyl ligands, carboxyl ligands, amide ligands, amine ligands, amino ligands, olefin ligands, etc., listed in L of the above general formula (a), ligands derived from hydroxy acid esters, ligands derived from β-diketones, ligands derived from β-keto esters, ligands derived from α,α-dicarboxylic acid esters, etc., and compounds having multiple hydroxyl groups may also be mentioned.

[0155] (A) In the metal-containing film-forming compound, the content of ligands from compounds containing the structure represented by formula (s) above is preferably 10 mol% to 90 mol% of the total ligands coordinated to the metal atom, more preferably 20 mol% to 80 mol%, and even more preferably 25 mol% to 75 mol%. For ligands other than those from compounds containing the structure represented by formula (s) above, such as alkoxy ligands from the above-mentioned ligand-forming compound (b) with 1 to 10 carbon atoms, the content of ligands is preferably 0 mol% to 90 mol% of the total ligands coordinated to the metal atom, and more preferably 20 mol% to 80 mol%.

[0156] Furthermore, in the synthesis reaction of (A) metal-containing film-forming compounds, (b) in addition to ligand-forming compounds, (c) silicon-containing compounds may also be added.

[0157] By replacing the hydrolyzable groups of (a) metal compound with silicon-containing compounds, the stability of (A) metal-containing film-forming compound in the metal-containing film-forming composition can be improved.

[0158] (c) Silicon-containing compounds, such as those with the structure of formula (w).

[0159] [Chemistry 11]

[0160]

[0161] In the formula, R A R B and R C It is any organic group selected from the following general formulas (w-1) to (w-3) having any crosslinking group having 2 to 30 carbons, substituted or unsubstituted alkyl groups having 1 to 20 carbons, and aryl groups having 6 to 20 carbons.

[0162] [Chemistry 12]

[0163]

[0164] In general formulas (w-1) to (w-3), R s It is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bonded part.

[0165] Regarding (c) silicon-containing compounds, any of the following compounds is preferred, and from a productive point of view, trimethylsilanol is preferred.

[0166] [Chemistry 13]

[0167]

[0168] When the metal-containing film-forming compound (A) comprises ligands from a compound having the structure represented by formula (s) above and ligands from the silicon-containing compound (c), the content of the ligands from the compound having the structure represented by formula (s) in the metal-containing film-forming compound (A) is preferably 10 mol% to 100 mol%, more preferably 20 mol% to 80 mol%, and even more preferably 25 mol% to 75 mol%. The content of the ligands from the silicon-containing compound (c) is preferably 10 mol% to 90 mol%, more preferably 20 mol% to 80 mol%, and even more preferably 25 mol% to 75 mol%. (b) The content of the compound for ligand formation and (c) the ligand other than the silicon-containing compound, such as the ligand from the alkoxy group having 1 to 10 carbon atoms, is preferably 0 to 90 mol% of the total content of the ligands located on the metal atom, and more preferably 0 to 75 mol%.

[0169] (A) There are no particular limitations on the synthesis method of the metal-containing membrane-forming compound. For example, (a) the metal compound can be obtained by reacting a metal alkoxide, metal carboxylate, or metal acetylacetonate (acac) with a ligand from a compound containing the structure represented by formula (s) above. (a) The metal compound can also be reacted with a ligand from a compound containing the structure represented by formula (s) above after hydrolysis and condensation, or by reacting (a) the metal compound with a ligand from a compound containing the structure represented by formula (s) above followed by hydrolysis and condensation. When hydrolysis and condensation are difficult to control, the reaction can be carried out in a non-aqueous environment with a ligand from a compound containing the structure represented by formula (s) above. These adjustments are preferable to suit the properties required for the metal-containing membrane-forming compound (A) and the metal-containing membrane. When a compound containing (c) a silicon-containing compound and a compound containing the structure represented by formula (s) above are used as ligands, it is preferable to react the (a) metal compound with the (c) silicon-containing compound and then react with the ligand from the compound containing the structure represented by formula (s) above.

[0170] Regarding the method of using a (a) metal compound for hydrolysis-condensation reaction, for example, methods such as carrying out the hydrolysis-condensation reaction of (a) metal compound in an aqueous solvent can be cited. In this case, other compounds having hydrolyzable groups can be added as needed. Furthermore, acids such as acetic acid can also be added as catalysts for the hydrolysis-condensation reaction. The lower limit of the amount of water used in this hydrolysis-condensation reaction is preferably 0.2 moles, more preferably 1 mole, and more preferably 3 moles, relative to the hydrolyzable groups possessed by the (a) metal compound. The upper limit of the above-mentioned amount of water is preferably 20 moles, more preferably 15 moles, and more preferably 10 moles.

[0171] (A) The solvent used in the synthesis reaction of metal-containing film-forming compounds is not particularly limited, for example, the solvents described below (B) are the same as those mentioned below. Typical solvents and solvent mixtures containing ester, ether, or alcohol functional groups, such as a mixture of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) in a volume ratio of 70 / 30. Other solvents that can be used include butanediol monomethyl ether, ethylene glycol monomethyl ether, butanediol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, butanediol monopropyl ether, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, 1-butanol, 2-butanol, 2-methyl-1-propanol, 4-methyl-2-pentanol, etc. Ketones, tetrahydrofuran, toluene, hexane, ethyl acetate, cyclohexanone, methyl pentanone, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipentyl ether, isopentyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol monotert-butyl ether acetate, γ-butyrolactone, methyl isobutyl ketone, cyclopentyl methyl ether, etc.

[0172] <(B) Solvent>

[0173] The solvent (B) that can be used in the metal-containing film-forming composition of the present invention is not particularly limited as long as it can dissolve the metal-containing film-forming compound (A) described above, and contains crosslinking agents (C), acid generators (D), surfactants (E), and other additives that may sometimes dissolve them.

[0174] Specifically, organic solvents such as those described in paragraphs

[0091] to

[0092] of Japanese Patent Application Publication No. 2007-199653 may be added. More specifically, it is preferable to use 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 mixtures containing one or more of these.

[0175] The amount of organic solvent incorporated is preferably 200 to 10,000 parts by mass relative to 100 parts by mass of the metal-containing film-forming compound (A), and more preferably 250 to 5,000 parts by mass.

[0176] <(B1) High-boiling-point solvents>

[0177] In the metal-containing film-forming composition of the present invention, the aforementioned solvent (B) also includes a high-boiling-point solvent (B1).

[0178] The aforementioned (B1) high-boiling-point solvent may also be one or more organic solvents with a boiling point of 180 degrees (°C) or higher.

[0179] For example, (B) solvent may also be a mixture of one or more organic solvents with a boiling point of less than 180°C and one or more organic solvents with a boiling point of 180°C or higher ((B1) high boiling point solvent).

[0180] (B1) Any high-boiling-point solvent is acceptable as long as it can dissolve all components of the metal-containing film-forming composition of the present invention. There are no special limitations such as hydrocarbons, alcohols, ketones, esters, ethers, or chlorinated solvents. Specific examples include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecylol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, and 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 mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, tri... Ethylene glycol-n-butyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetin, propylene glycol diacetate, Dipropylene glycol methyl 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, etc., can be used alone or in combination.

[0181] (B1) The high-boiling-point solvent can be appropriately selected from the above, for example, to match the temperature at which the metal-containing film-forming composition of the present invention is heat-treated. (B1) The boiling point of the high-boiling-point solvent is preferably 180°C to 300°C, and more ideally 200°C to 300°C. With such a boiling point, there is no risk of excessively rapid volatilization during baking (heat treatment), thus suppressing defects caused by drying during film formation. Furthermore, with such a boiling point, it will not remain in the film after baking without volatilization, thus avoiding any adverse effects on film properties such as etching resistance.

[0182] Furthermore, when using a high-boiling-point solvent (B1), the mixing amount is preferably 1 to 30 parts by mass relative to 100 parts by mass of an organic solvent with a boiling point not reaching 180°C. Such a mixing amount can impart sufficient thermal fluidity during baking, will not remain in the film, and will not cause deterioration of film properties such as etching resistance, which is ideal.

[0183] <Other Ingredients>

[0184] When a metal-containing film-forming composition that functions as a metal-containing film material used in semiconductor manufacturing is a metal-containing film-forming composition containing (A) a metal-containing film-forming compound and (B) an organic solvent as described above, the metal-containing film-forming composition may further contain one or more of (C) a crosslinking agent, (D) an acid generating agent, and (E) a surfactant.

[0185] The following describes the components that can be contained in the metal-containing film-forming composition of the present invention, other than (A) the metal-containing film-forming compound and (B) the organic solvent mentioned above.

[0186] [(C) Crosslinking agent]

[0187] In the metal-containing film-forming composition of the present invention, a crosslinking agent (C) may be added to improve curability and further suppress mixing with the upper layer of the resist film. There are no particular limitations on the crosslinking agent; a wide range of known crosslinking agents can be used. Examples include melamine-based crosslinking agents, glycourea-based crosslinking agents, benzoguanamine-based crosslinking agents, urea-based crosslinking agents, β-hydroxyalkylamide-based crosslinking agents, isocyanurate-based crosslinking agents, aziridine-based crosslinking agents, oxazoline-based crosslinking agents, epoxy-based crosslinking agents, and phenol-based crosslinking agents. The aforementioned crosslinking agent (C) can be used alone or in combination of two or more. The amount of crosslinking agent added is preferably 5 to 50 parts, more preferably 10 to 40 parts, relative to 100 parts of the metal-containing film-forming compound (A) mentioned above. An amount of 5 parts or more will exhibit sufficient curability and suppress mixing with the upper layer of the resist film. On the other hand, if the amount added is less than 50 parts, there is no risk of deterioration in dry etching resistance due to a decrease in the proportion of (A) metal-containing film-forming compounds in the composition.

[0188] Specifically, melamine-based crosslinking agents include, for example, hexamethoxymethylated melamine, hexabutoxymethylated melamine, their alkoxy and / or hydroxy substituted forms, and their partially self-condensing forms.

[0189] Glycourea is a crosslinking agent, specifically, for example, tetramethoxymethylated glycourea, tetrabutoxymethylated glycourea, their alkoxy and / or hydroxy substituted forms, and their partially self-condensing forms.

[0190] Benzoguanidine is a crosslinking agent, specifically, for example, tetramethoxymethylated benzoguanidine, tetrabutoxymethylated benzoguanidine, their alkoxy and / or hydroxy substituted forms, and their partially self-condensing forms.

[0191] Urea crosslinking agents, specifically, such as dimethoxymethylated dimethoxyethylurea, its alkoxy and / or hydroxy substituted derivatives, and their partial self-condensation derivatives.

[0192] β-hydroxyalkylamide crosslinking agents, specifically, for example, N,N,N',N'-tetra(2-hydroxyethyl)hexamethylenediamide.

[0193] Isocyanurate crosslinking agents, specifically, for example, trioxypropyl isocyanurate and triallyl isocyanurate.

[0194] Aziridine crosslinking agents, specifically, for example, 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-dihydroxymethylbutanol-tris[3-(1-aziridine)propionate].

[0195] Oxazoline-based crosslinking agents, specifically, for example, 2,2'-isopropylidene bis(4-benzyl-2-oxazoline), 2,2'-isopropylidene bis(4-phenyl-2-oxazoline), 2,2'-isopropylidene bis(4-phenyl-2-oxazoline), 2,2'-methylenebis4,5-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), and 2-isopropylidene oxazoline copolymers.

[0196] Epoxy crosslinking agents, specifically, include diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,4-cyclohexanediethanol diglycidyl ether, poly(glycidyl methacrylate), trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, and neopentyl tertetrol tetraglycidyl ether.

[0197] Phenolic crosslinking agents, specifically, for example, compounds represented by the following general formula (10).

[0198] [Chemistry 14]

[0199]

[0200] In the formula, Q is a single bond, or a q bond with 1 to 20 carbon atoms. 1 Valence hydrocarbon group. R 16 It consists of hydrogen atoms or alkyl groups having 1 to 20 carbon atoms. q 1 It is an integer from 1 to 5.

[0201] Q is a single bond, or q with 1 to 20 carbon atoms. 1 Valence hydrocarbon group. q 1 The value should be an integer from 1 to 5, with 2 or 3 being preferred. Specifically, exclude, for example, methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylisopropylbenzene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, and eicosane. 1 A group consisting of one hydrogen atom. R 16 It is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Specifically, alkyl groups having 1 to 20 carbon atoms include, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, octyl, ethylhexyl, decyl, and eicosyl, preferably having a hydrogen atom or a methyl group.

[0202] Examples of compounds represented by the above general formula (10) include the following compounds. Among them, considering the curability of the sealing film and the improvement of film thickness uniformity, triphenol methane, triphenol ethane, 1,1,1-tris(4-hydroxyphenyl)ethane, and the hexamethoxymethylated form of tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene are preferred.

[0203] [Chemistry 15]

[0204]

[0205] In the formula, R 16 Same as equation (10) above.

[0206] [Chemistry 16]

[0207]

[0208] In the formula, R 16 Same as equation (10) above.

[0209] <(D) Acid Generators>

[0210] In the metal-containing film-forming composition of the present invention, an acid-generating agent may be added to further promote the curing reaction of the metal-containing film-forming compound described in (A). The acid-generating agent may include those that generate acid through thermal decomposition or those that generate acid through light irradiation. Specifically, materials described in paragraphs

[0061] to

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

[0211] The above-mentioned acid generating agent can be used alone or in combination of two or more. The amount of acid generating agent added is preferably 0.05 to 50 parts by weight relative to 100 parts by weight of the metal-containing film-forming compound in (A) above, and more preferably 0.1 to 10 parts by weight.

[0212] <(E) Surfactants>

[0213] In the metal-containing film-forming composition of the present invention, a surfactant (E) may be added to improve the coatability of spin coating. The surfactant, for example, may be one described in

[0142] to

[0147] of Japanese Patent Application Publication No. 2009-269953. The amount of surfactant added is preferably 0.01 to 10 parts by weight relative to 100 parts by weight of the metal-containing film-forming compound (A) described above, and more preferably 0.05 to 5 parts by weight.

[0214] <Methods for forming metal-containing films>

[0215] The present invention provides a method for forming a metal-containing film that acts as a multilayer resist film used in photolithography or a planarization film for semiconductor manufacturing using the above-described metal-containing film forming composition.

[0216] This invention utilizes a metal-containing film formation method for a metal-containing film formation composition, wherein the aforementioned metal-containing film formation composition is coated onto a substrate using a spin coating method or the like. By using a spin coating method, good embedding characteristics can be obtained. After spin coating, the solvent is evaporated, and to prevent mixing with the upper and intermediate resist films and to promote crosslinking reactions, baking (heat treatment) is performed. Baking is preferably performed within the range of 100°C to 600°C for 10 to 600 seconds, more preferably within the range of 150°C to 500°C for 10 to 300 seconds. Considering the impact on device damage and wafer deformation, the upper limit of the heating temperature in the wafer processing for photolithography is preferably set to 600°C or less, more preferably 500°C or less.

[0217] Furthermore, the metal-containing film forming method using the metal-containing film forming composition of the present invention can coat the metal-containing film forming composition of the present invention onto a substrate to be processed using the same spin coating method as described above, and then harden the metal-containing film forming composition by firing it in a gas environment with an oxygen concentration of 0.1% to 21% by volume, thereby forming a metal-containing film.

[0218] The metal-containing film-forming composition of the present invention can obtain a fully hardened film by firing in such an oxygen environment. While air is acceptable in the baking atmosphere, it is ideal to pre-seal in inert gases such as N2, Ar, or He to reduce oxygen levels and prevent oxidation of the metal-containing film. To prevent oxidation, the oxygen concentration needs to be controlled, preferably below 1000 ppm, and more preferably below 100 ppm (by volume). Preventing oxidation of the metal-containing film during baking prevents increased absorption or decreased etching resistance, which is ideal.

[0219]

[0220] Furthermore, the present invention provides a pattern forming method, which is a pattern forming method performed by multilayer photoresist treatment using the above-mentioned metal-containing film forming composition.

[0221] A method for forming a pattern on a substrate being processed, characterized by comprising the following steps:

[0222] (I-1) After directly or indirectly coating the aforementioned metal-containing film-forming composition onto the substrate to be processed, a heat treatment is performed to form a metal-containing film.

[0223] (I-2) A photoresist material is used directly or indirectly on the aforementioned metal-containing film to form a photoresist top layer film.

[0224] (I-3) After exposing the aforementioned upper resist film to a pattern, develop it with a developer to form a pattern on the aforementioned upper resist film.

[0225] (I-4) Using the aforementioned patterned resist film as a mask, the pattern is directly or indirectly transferred to the aforementioned metal-containing film by dry etching.

[0226] (I-5) Using the aforementioned patterned metal-containing film as a mask, the aforementioned substrate is directly or indirectly processed to form a pattern on the aforementioned substrate.

[0227] (3 layers of corrosion resist treatment)

[0228] For example, a pattern forming method is provided, which is a pattern forming method using a three-layer resist treatment with the above-mentioned metal-containing film forming composition. The method 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 invention; forming an upper resist film on the metal-containing film using a photoresist material; exposing the upper resist film to a pattern; developing the upper resist film with a developer to form a pattern on the upper resist film; using the patterned upper resist film as a mask; transferring the pattern to the aforementioned metal-containing film by dry etching; using the patterned metal-containing film as a mask; 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 to process the substrate to form a pattern on the substrate.

[0229] The patterning method using three layers of resist is shown in Figure 1First, an organic resist underlayer film 2 (IA) is formed on the substrate 1 to be processed using an organic resist underlayer film material. Then, a metal-containing film 3 (IB) is formed on the organic resist underlayer film 2 using the metal-containing film forming composition of the present invention. Then, an upper resist film 4 (IC) is formed on the metal-containing film 3 using a photoresist material. After exposure P (ID) using a mask 5, the upper resist film 4 and the metal-containing film 3 are exposed (IE) to form an upper resist film pattern 4a (IF) on the upper resist film 4. Using the obtained upper resist film pattern 4a as a mask, the pattern is transferred to the metal-containing film 3 (IG) by dry etching. After removing the upper resist film pattern 4a, the obtained metal-containing film pattern 3a is used as a mask to transfer the pattern to the organic resist underlayer film 2 by dry etching to transfer the organic resist underlayer film pattern 2a (IH). After removing the metal-containing film pattern 3a, the obtained organic resist lower film pattern 2a is used as a mask to process the substrate 1 to form pattern 1a(II) on the substrate.

[0230] Since the upper resist film treated with the above three layers of resist exhibits resistance to etching by halogen gases such as chlorine-based gases and fluorine-based gases, it is preferable to use an etching gas with halogen-based gases as the main component for dry etching of the metal-containing film using the upper resist film as a mask in the above three-layer resist treatment.

[0231] The metal-containing film treated with the above three layers of photoresist exhibits resistance to etching with oxygen-based gases. Therefore, in the above three-layer photoresist treatment, it is better to use an etching gas with oxygen-based gases as the main component for dry etching of the organic photoresist underlayer film, which uses the metal-containing film as a mask.

[0232] The organic resist underlayer film treated with the above three layers of resist exhibits resistance to etching with fluorine-based gases. Therefore, in the above three-layer resist treatment, it is preferable to use an etching gas with fluorine-based gases as the main component for dry etching of the substrate being processed using the organic resist underlayer film as a mask.

[0233] The organic photoresist underlayer film materials that can be used in the above-mentioned organic photoresist underlayer film include those already known as underlayer films for the three-layer photoresist method or the two-layer photoresist method using a silicone photoresist composition, 4,4'-(9-fluoreneyl)bisphenol phenolic varnish resin (molecular weight 11,000) as disclosed in Japanese Patent Application Publication No. 2005-128509, and various resins represented by phenolic varnish resin that are known as photoresist underlayer film materials for the two-layer and three-layer photoresist methods. Furthermore, if it is desired to further improve the heat resistance compared to ordinary phenolic varnish resins, a polycyclic skeleton such as 6,6'-(9-fluoreneyl)-bis(2-naphthol)phenolic varnish resin may be added. In addition, polyimide resins (e.g., Japanese Patent Application Publication No. 2004-153125) may be further selected.

[0234] The aforementioned organic photoresist underlayer film can be formed on the substrate using a composition solution, similar to the photoresist composition, via spin coating or the like. After forming the organic underlayer film using spin coating or the like, it is advisable to bake it to allow the organic solvent to evaporate. The baking temperature is preferably in the range of 80–400°C, and the baking time is preferably in the range of 10–300 seconds.

[0235] The organic hard mask formed by CVD or ALD can also be used to replace the underlying organic resist material.

[0236] In the above pattern formation method, the upper resist film can be either positive or negative, and can be the same as commonly used photoresist composition. When forming the upper resist film using the above photoresist composition, it can be formed by spin coating or by vapor deposition using CVD or ALD.

[0237] When forming a photoresist composition using spin coating, pre-baking after resist coating is preferred, preferably within the range of 60–180°C for 10–300 seconds. Afterwards, exposure is performed as usual, followed by post-exposure baking (PEB) and development to obtain the resist pattern. Furthermore, the thickness of the upper resist film is not particularly limited, but 10–500 nm, especially 20–400 nm, is preferred.

[0238] The exposure light is high-energy radiation with a wavelength below 300nm, specifically such as excimer lasers of 248nm, 193nm, and 157nm, soft X-rays of 3-20nm, electron beams, and X-rays.

[0239] As a method for forming the pattern of the above-mentioned resist upper film, the pattern can be formed by optical lithography with a wavelength of 5 nm to 300 nm, direct drawing using an electron beam, nanoimprinting, or a combination thereof. In this invention, EUV light is the most ideal.

[0240] Furthermore, the development method of the aforementioned pattern forming method is preferably alkaline development or development using organic solvents.

[0241] Then, the obtained resist pattern is used as a mask for etching. In the etching of the metal-containing film in the three-layer resist treatment, chlorine-based and chlorofluorocarbon-based gases are used, with the upper resist pattern used as a mask. This forms a metal-containing film pattern.

[0242] Then, the obtained metal-containing film pattern is used as a mask for etching the organic resist underlayer film. It is preferable to use an oxygen-based gas as the primary etching gas for etching the organic resist underlayer film.

[0243] The metal-containing film obtained by means of the metal-containing film forming composition of the present invention has the characteristic of excellent etching resistance when the underlying film of these organic resists is etched.

[0244] Secondly, etching of the workpiece can also be performed using conventional methods. For example, if the workpiece is a low dielectric constant insulating film based on SiO2, SiN, or silicon dioxide, etching can be performed using chlorofluorocarbon gas as the main component.

[0245] Furthermore, there are no special limitations on the substrate to be processed (the substrate to be processed), and substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al, or films on which the layer to be processed is formed, can be used. The layer to be processed can be various Low-k films and their barrier films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, and thicknesses of 50–10,000 nm, especially 100–5,000 nm, can typically be formed. Also, the substrate and the layer to be processed can be made of different materials when forming the layer to be processed.

[0246] (Two layers of corrosion resist treatment)

[0247] Furthermore, the present invention provides a pattern forming method, which is a pattern forming method using two layers of photoresist treated with the above-mentioned metal-containing film forming composition. The method is characterized by forming a metal-containing film on a substrate to be processed using a metal-containing film forming composition, forming a photoresist top layer film on the metal-containing film using a photoresist material, exposing the photoresist top layer film to a pattern, developing the photoresist top layer film with a developer to form a pattern on the photoresist top layer film, using the patterned photoresist top layer film as a mask, transferring the pattern to the metal-containing film by dry etching, and using the patterned metal-containing film as a mask to process the substrate to be processed by dry etching to form a pattern on the substrate.

[0248] The metal-containing film obtained by means of the metal-containing film forming composition of the present invention has the characteristic of excellent etching resistance when etching the substrate being processed. Therefore, in the above two-layer resist treatment, it is preferable to use an etching gas mainly composed of fluorine-based gases for dry etching of the substrate being processed using the metal-containing film as a mask.

[0249] (Peeling steps for metal-containing films)

[0250] Furthermore, in the aforementioned pattern forming method, after processing the film directly beneath the aforementioned metal-containing film (hereinafter referred to as the processed film; for example, in the case of the aforementioned 3-layer resist treatment, it refers to the lower layer film of the organic resist, and in the case of the aforementioned 2-layer resist treatment, it refers to the processed substrate), it is preferable to include a step of removing the metal-containing film remaining on the pattern of the processed film with a chemical solution. When this step is performed after the aforementioned processed film etching step, it removes the metal-containing film remaining on the upper side of the substrate. Also, this step can be performed on the patterned or unpatterned metal-containing film before the aforementioned substrate etching step.

[0251] The wet stripping method is shown in Figure 2 For a processed body having an organic resist lower layer film 2, a metal-containing film 3, and a resist upper layer film 4 formed on a substrate 1, firstly, mask exposure is performed on the resist upper layer film 4. Then, development and rinsing are performed to form a resist upper layer film pattern 4a. Next, using the obtained resist upper layer film pattern 4a as a mask, the pattern is transferred to the metal-containing film 3 by dry etching to obtain a metal-containing film pattern 3a. Then, the resist upper layer film pattern 4a is removed, and the obtained metal-containing film pattern 3a is used as a mask to transfer the pattern to the organic resist lower layer film 2 by dry etching to obtain an organic resist lower layer film pattern 2a. Finally, the metal-containing film pattern 3a is removed by wet stripping.

[0252] The metal-containing film of the present invention can be removed using a chemical solution and wet processing, thus allowing patterns to be formed without damaging the substrate being processed.

[0253] The methods for removing metal-containing films described above include, for example, dry etching of the metal-containing film and contacting the metal-containing film with liquids such as alkaline or acidic solutions.

[0254] For acid removal solutions, there are no particular limitations if the solution contains acid. However, considering the need to further improve the removal performance of metal-containing membranes, liquids containing hydrogen peroxide and acid are preferred. More specifically, aqueous solutions containing hydrochloric acid and hydrogen peroxide (SC-2 chemical solution), aqueous solutions containing sulfuric acid and hydrogen peroxide (SPM chemical solution), or aqueous solutions containing hydrofluoric acid and hydrogen peroxide (FPM chemical solution) are particularly preferred.

[0255] The alkali removal solution is not particularly limited if it is an alkaline solution containing alkali. Examples of alkalis include 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, etc. Among these, ammonia is preferred from the perspective of avoiding damage to the substrate.

[0256] For alkaline removal solutions, considering the viewpoint of further improving the removal performance of metal-containing membranes, solutions containing alkali and water, or solutions containing alkali, hydrogen peroxide and water, are preferred. More specifically, mixed aqueous solutions of ammonia and hydrogen peroxide (25% ammonia solution / 30% hydrogen peroxide solution / water = 1 / 2 / 40 mixed aqueous solution, 25% ammonia solution / 30% hydrogen peroxide solution / water = 1 / 1 / 5 mixed aqueous solution, etc. (SC1)) are particularly preferred.

[0257] The wet peeling method is not particularly limited if it involves contacting the metal-containing film with the peeling chemical solution for a certain period of time under heating conditions. Examples include immersing a substrate with a metal-containing film in heated alkaline hydrogen peroxide, blowing alkaline hydrogen peroxide under heating conditions, and coating with heated alkaline hydrogen peroxide. After each of the above methods, the substrate can be washed with water and dried.

[0258] The lower limit of the temperature for removing metal-containing films using a stripping chemical solution is preferably 23°C, 40°C is preferred, and 50°C is even better. The upper limit of the above temperature is preferably 100°C, and 90°C is even better.

[0259] The lower limit of the immersion time in the immersion method is preferably 1 second, 10 seconds is better, 20 seconds is even better, and 30 seconds is especially good. Considering the point of view of suppressing the impact on the substrate, the upper limit of the above immersion time is preferably 60 minutes, 30 minutes is better, 20 minutes is even better, and 10 minutes is especially good.

[0260] [Example]

[0261] The present invention will be described in more detail below with examples of synthesis, comparative examples of synthesis, examples, and comparative examples, but the invention is not limited thereto.

[0262] [Synthesis example]

[0263] The following synthesis examples and comparative examples use organic group raw materials G: (G1) to (G7) and silicon-containing organic group raw material H1: (trimethylsilanol).

[0264] Raw material groups G: (G1)~(G7) are shown below.

[0265] [Chemistry 17]

[0266]

[0267] Metal source M, using the following metal compound.

[0268] (M1): Tetraisopropoxytitanium (Sigma-Aldrich Corp, 377996)

[0269] (M2): Zr(OBu)4: Tetrabutoxyzirconium (IV) (80% by mass 1-butanol solution) (Tokyo Chemical Industry Co., Ltd., Z0016)

[0270] (M3): Hf(OBu)4: n-Butoxyhafnium(IV) (Sigma-Aldrich Corp, 667943)

[0271] [Synthetic Example 1] Synthesis of a metal-containing film-forming compound (A-1)

[0272] Under nitrogen atmosphere, 7.10 g of tetraisopropoxytitanium (M1) was dissolved in 15.00 g of PGMEA / PGME (70 / 30 by weight) solution. While stirring, the reaction temperature was increased to 60 °C. A mixture containing 4.70 g of compound G1 suspended in 5.50 g of PGMEA / PGME (70 / 30 by weight) solution was added to the reaction system, and the reaction was continued at 60 °C with stirring for 1 hour. After cooling to room temperature, the obtained reaction solution was filtered through a 0.45 μm PTFE filter to obtain a PGMEA / PGME solution of the metal-containing film-forming compound (A-1).

[0273] [Synthesis of compounds (A-2) to (A-5) and comparative examples (R-1) to (R-2)]

[0274] Using the metal source M, compound group G, and compound group H as shown in Table 1, and except for the reaction conditions as described in [Synthetic Example 1], compounds (A-2) to (A-5) and comparative examples (R-1) to (R-2) shown in Table 1 were obtained. (A-1) is also shown in Table 1.

[0275] [Table 1]

[0276]

[0277] [Synthetic Example 8] Synthesis of a metal-containing film-forming compound (A-6)

[0278] Under nitrogen atmosphere, 12.00 g of tetrabutoxyzirconium (IV) (M2) was dissolved in 15.00 g of PGMEA / PGME (70 / 30 by weight) solution. While stirring, the reaction temperature was increased to 50 °C, and 6.76 g of compound H1 was added dropwise to the aforementioned solution. After the addition, the reaction temperature was set to 60 °C and stirring continued for 2 hours. Then, a mixture containing 3.05 g of compound G4 suspended in 5.50 g of PGMEA / PGME (70 / 30 by weight) solution was added to the aforementioned reaction system, and the reaction temperature was maintained at 60 °C while stirring continued for 1 hour. After cooling to room temperature, the obtained reaction solution was filtered through a 0.45 μm PTFE filter to obtain a PGMEA / PGME solution of the metal-containing film-forming compound (A-6).

[0279] [Synthetic Example 9] Synthesis of a metal-containing film-forming compound (A-7)

[0280] Under nitrogen atmosphere, 59.95 g of tetrabutoxyzirconium (IV) (M2) was dissolved in 50.00 g of 1-butanol. While stirring, a solution of 1.69 g of deionized water in 70.00 g of 2-butanol was added dropwise over 2 hours at room temperature. 26.53 g of compound G4 was added to the resulting solution, and the mixture was stirred at room temperature for 30 minutes. The solution was concentrated under reduced pressure at 30°C, then heated to 60°C and heated under reduced pressure until no distillate appeared. After no distillate was observed, 100.50 g of a PGMEA / PGME (70 / 30 by weight) solution was added, and the mixture was heated at 40°C under reduced pressure until IPA no longer distilled off, yielding a PGMEA / PGME solution containing the metal-containing film-forming compound (A-7).

[0281] Preparation of metal-containing film forming compositions (UDL-1 to 10, comparative UDL-1 to 2)

[0282] The metal-containing film-forming compositions were prepared using the aforementioned polymers (A-1) to (A-7), (D-1) as an acid generator, (XL-1) to (XL-2) as a crosslinking agent, and (F1: ethylene glycol dibenzyl ether, boiling point 364°C) as a high-boiling solvent (B1). After being dissolved in organic solvents at the proportions shown in Table 2, the compositions (UDL-1 to 10, comparative examples UDL-1 to 2) were prepared by filtering through a 0.1 μm fluororesin filter.

[0283] [Chemistry 18]

[0284] (CH3CH2)3N + H

[0285] C4F9SO3 -

[0286] (D-1)

[0287]

[0288] [Table 2]

[0289]

[0290] [Etching Resistance Evaluation]

[0291] Metal-containing film forming compositions (UDL-1 to 10 and comparative examples UDL-1 to 2) were coated on a silicon substrate, and a metal-containing film (film thickness a) with a thickness of 30 nm was formed by heating at 250°C for 60 seconds using a heating plate.

[0292] Comparative Examples 1-3 involve coating the following silicon-containing photoresist interlayer material (SOG-1) and baking it at 220°C for 60 seconds to form a photoresist interlayer film with a thickness of 30 nm (film thickness a).

[0293] The silicon-containing photoresist interlayer material (SOG-1) is prepared by dissolving a polymer represented by ArF silicon-containing interlayer polymer (SiP1) and a thermal crosslinking catalyst (CAT1) in a solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M) at the proportions shown in Table 3, and filtering the solution through a fluoropolymer filter with a pore size of 0.1 μm.

[0294] [Table 3]

[0295]

[0296] The structural formulas of the ArF-containing silicon interlayer polymer (SiP1) and the thermal crosslinking catalyst (CAT1) used are shown below.

[0297] [Chemistry 19]

[0298]

[0299] Comparative Examples 1-4 involve coating the following organic resist underlayer material (SOC-1) and baking it at 350°C for 60 seconds to form a resist underlayer film (film thickness a) with a thickness of 50 nm.

[0300] Organic photoresist underlayer membrane material (SOC-1) is prepared by dissolving a polymer represented by organic underlayer membrane polymer (CP1) in a solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M) at the proportions shown in Table 4, and filtering the solution through a fluoropolymer filter with a pore size of 0.1 μm.

[0301] [Table 4]

[0302]

[0303] The structural formula of the organic lower membrane polymer (CP1) used is shown below.

[0304] [Chemistry 20]

[0305]

[0306] Mw = 7,000, Mw / Mn = 3.50

[0307] Then, etching was performed using CF4 gas and O2 gas respectively under the following conditions using the ULVAC CE-300I etching apparatus, and the film thickness b was measured. The film thickness etched in 1 minute (film thickness a - film thickness b) was calculated from the film thickness etched using each gas within a specified time as the etching rate (nm / min).

[0308] For the etching rate of CF4 gas, a value below 20 nm / min is judged as "A (Excellent)", a value between 20 nm / min and 30 nm / min is judged as "B (Good)", and a value above 30 nm / min is judged as "C (Poor)".

[0309] For the etching rate of O2 gas, a value below 20 nm / min is judged as "A (Excellent)", a value between 20 nm / min and 30 nm / min is judged as "B (Good)", and a value above 30 nm / min is judged as "C (Poor)".

[0310] The results are shown in Table 5.

[0311] Dry etching conditions using CF4 gas

[0312] Pressure: 3 Pa

[0313] Antenna RF power: 100W

[0314] Bias RF power: 15W

[0315] CF4 gas flow rate: 15 sccm

[0316] Time: 30 seconds

[0317] Dry etching conditions using O2 gas

[0318] Pressure: 3 Pa

[0319] Antenna RF power: 300W

[0320] Bias RF power: 10W

[0321] O2 gas flow rate: 25 sccm

[0322] Time: 30 seconds

[0323] [Table 5]

[0324]

[0325] As shown in Table 5, the metal-containing film-forming compositions (UDL-1 to 10) of the present invention exhibit excellent etching resistance to both CF4 gas and O2 gas.

[0326] The SOG-1 used in Comparative Examples 1-3 exhibits excellent resistance to etching using O2 gas, making it suitable for three-layer resist processing where it is combined with an organic resist underlayer film and the resist pattern is transferred onto the substrate being processed.

[0327] The SOC-1 used in Comparative Examples 1-4 exhibits excellent etching resistance to CF4 gas, making it suitable for two-layer resist processing that combines with a photoresist top film and transfers the resist pattern onto the substrate being processed.

[0328] [Wet Etching Test of Coated Film]

[0329] Metal-containing film-forming compositions (UDL-1 to 10, and comparative examples UDL-1 to 2) and SOG-1 were coated onto a silicon substrate. The substrate was then heated at 250°C for 60 seconds using a hot plate to form a metal-containing film with a thickness of 30 nm. These metal-containing films were immersed in an alkaline solution (a 1 / 1 / 5 mixture of 25% ammonia solution / 30% hydrogen peroxide solution / water) at 65°C for 2 minutes. The remaining film thickness was measured using a JA Woollam M-2000 high-speed spectrophotometer, and the change in film thickness before and after alkaline immersion was evaluated. Film thickness changes of 70% or more were rated as "good," while those with changes of less than 70% were rated as "poor."

[0330] The results are shown in Table 6.

[0331] [Table 6]

[0332]

[0333] As shown in Table 6, the metal-containing film-forming compositions of the present invention (UDL-1 to 10) exhibit better peelability using an alkaline solution compared to the metal-containing film formed by Comparative Example UDL-1, which does not contain ligands from organic sulfonic acid compounds, and the silicon-containing film formed by SOG-1. It is speculated that the permeability of the peeling solution is improved due to the inclusion of ligands from organic sulfonic acid compounds.

[0334] [Patterning Experiment]

[0335] On a silicon wafer with a 100 nm SiO2 film, a SOC film (ODL-306 with 61 atomic% carbon content) manufactured by Shin-Etsu Chemical Industry Co., Ltd. as an organic resist underlayer was applied by spin coating and baked at 350°C for 60 seconds to form a carbon film with a thickness of 50 nm. Then, the aforementioned metal-containing film-forming compositions (UDL-1 to 10, and comparative examples UDL-1 to 2) and SOG-1 were coated on the organic resist underlayer, and a resist intermediate film with a thickness of 30 nm was formed by heating at 250°C or 220°C for 60 seconds using a hot plate.

[0336] Next, the photoresist material shown in Table 7 was spin-coated onto the aforementioned metal-containing film, and a 40 nm thick photoresist film was pre-baked at 105 °C for 60 seconds using a hot plate. Exposure was then performed using an ASML EUV scanning exposure machine NXE3300 (NA 0.33, σ 0.9 / 0.6, dipole illumination, L / S pattern with a pitch of 36 nm on the wafer). PEB was applied at 100 °C for 60 seconds on a hot plate, followed by development with a 2.38% (w / w) TMAH aqueous solution for 30 seconds to obtain a pattern with a line size of 22 nm.

[0337] The length of the line was measured using a Hitachi Advanced Semiconductor Magnetic Electron Microscope (CG5000), and pattern collapse was observed. No pattern collapse was rated as good, and pattern collapse was rated as poor. Furthermore, the cross-sectional shape was observed using a Hitachi Advanced Semiconductor Magnetic Electron Microscope (S-4800). No tailing shape was observed, and a noticeable tailing shape was rated as poor.

[0338] Furthermore, the exposure amount with a line size of 18nm was used as the sensitivity evaluation, and it was determined that the less the exposure amount, the more it helps to increase the sensitivity of the upper layer of the resist film.

[0339] The results are shown in Table 8.

[0340] [Chemistry 21]

[0341] polymer:

[0342]

[0343] [Chemistry 22]

[0344]

[0345] Surfactant: 3M FC-4430

[0346] [Table 7]

[0347]

[0348] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0349] CyHO (Cyclohexanone)

[0350] PGME (Propylene Glycol Monomethyl Ether)

[0351] [Table 8]

[0352]

[0353]

[0354] As shown in Table 8, the metal-containing film-forming compositions (UDL-1 to 10) of the present invention were confirmed to produce vertically shaped pattern cross-sections without pattern collapse during the formation of 22 nm linewidth patterns using EUV exposure. It is speculated that the metal-containing film-forming compounds of the present invention, containing at least one of unsaturated hydrocarbon groups excluding aromatic rings and alkoxy groups, will improve adhesion to the resist pattern. Furthermore, it is speculated that the inclusion of a sulfonic acid structure will improve the permeability of the developer, resulting in a resist pattern with high rectangularity after development. Moreover, it is known that using the metal-containing film of the present invention as a resist underlayer film allows for the formation of resist patterns with high sensitivity.

[0355] On the other hand, it can be seen that Comparative Example UDL-1, which uses a compound without a sulfonyl group as a ligand, and Comparative Example UDL-2, which uses an organic sulfonic acid compound with a structure different from that of Formula (s) as a ligand, have a smaller effect on suppressing the collapse of fine line patterns compared to the metal-containing film-forming compositions of the present invention (UDL-1 to 10). Comparative Example 3-3, which uses SOG-1, did not observe pattern collapse, but the cross-sectional shape of the resist was a trailing shape.

[0356] As described above, the present invention has excellent adhesion to the upper resist, thus forming a metal-containing film with high collapse suppression effect for fine line patterns, which in turn helps to improve the sensitivity of the upper resist. It can also be easily removed, so it has high application value in the field of EUV lithography.

[0357] This specification contains the following specifications.

[0358] [1] A metal-containing film-forming compound, which is (A) a metal-containing film-forming compound, characterized in that:

[0359] The (A) metal-containing film-forming compound comprises at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the metal atom.

[0360] At least one of the ligands is derived from an organic sulfonic acid compound represented by the following formula (s).

[0361] [Chemistry 23]

[0362]

[0363] In the formula, R0 represents a monovalent organic group containing one or more of an unsaturated hydrocarbon group excluding an aromatic ring and an alkoxy group, having 1 to 30 carbon atoms.

[0364] [2] A metal-containing film-forming compound, such as [1], wherein the RO is a monovalent organic group containing one or more of vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, and alkoxy groups having 1 to 30 carbon atoms.

[0365] [3] A metal-containing film-forming compound as in [2], wherein the R0 is an alkyl group having 2 to 30 carbon atoms or an aryl group having 7 to 30 carbon atoms, selected from one or more of the functional groups of vinyl, allyl, allyloxy, ethynyl, propynyl, propynyloxy, and alkoxy.

[0366] [4] A metal-containing film-forming compound, as in [3], wherein the R0 is an aryl group containing 7 to 30 carbons selected from one or more of the functional groups of vinyl, allyl, allyloxy, ethynyl, propynyl, propynyloxy, and alkoxy.

[0367] [5] A metal-containing film-forming compound of any one of [1] to [4], wherein the (A) metal-containing film-forming compound further comprises a ligand from a silicon compound represented by the following general formula (w),

[0368] [Chemistry 24]

[0369]

[0370] In the formula, R A R B and R C It is any organic group selected from the following general formulas (w-1) to (w-3) having any crosslinking group having 2 to 30 carbons, substituted or unsubstituted alkyl groups having 1 to 20 carbons, and aryl groups having 6 to 20 carbons.

[0371] [Chemistry 25]

[0372]

[0373] In general formulas (w-1) to (w-3), R s It is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bonded part.

[0374] [6] A metal-containing film-forming compound of any one of [1] to [5], wherein the (A) metal-containing film-forming compound is a reaction product of a metal compound represented by formula (a), or a metal compound containing any of the following: hydrolysate, condensate, and hydrolysate-condensate of a metal compound represented by formula (a), and a compound containing the structure represented by formula (s).

[0375] [Chemistry 26]

[0376] L a MX b (a)

[0377] In the formula, M is any of Ti, Zr, and Hf, L is a monodentate or polydentate ligand with 1 to 30 carbon atoms, and X is selected from halogen atoms, alkoxy groups, carboxylic acid groups, acyloxy groups, and -NR. 1 R 2 Hydrolyzable groups, R 1 and R 2 Each is an independent hydrogen atom or a monovalent organic group with 1 to 20 carbon atoms, a + b = 2 to 4, where a and b are integers from 0 to 4.

[0378] [7] A metal-containing film-forming compound, such as [6], wherein formula (a) has the structure of formula (a-1).

[0379] [Chemistry 27]

[0380] M(OR 1A )4 (a-1)

[0381] 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.

[0382] [8] A metal-containing film forming composition that functions as a metal-containing film material used in semiconductor manufacturing, characterized in that it contains (A) a metal-containing film forming compound and (B) an organic solvent as described in any one of [1] to [7].

[0383] [9] A metal-containing film-forming composition as in [8], wherein the composition further contains one or more of (C) a crosslinking agent, (D) an acid generating agent, and (E) a surfactant.

[0384]

[10] A metal-containing film-forming composition such as [8] or [9], wherein the (B) organic solvent contains one or more organic solvents having a boiling point of 180°C or higher as (B1) high-boiling point solvents.

[0385]

[11] A pattern forming method, characterized by comprising the following steps:

[0386] (I-1) After directly or indirectly coating a metal-containing film-forming composition of any one of [8] to

[10] onto a substrate to be processed, a heat treatment is performed to form a metal-containing film.

[0387] (I-2) A photoresist material is used directly or indirectly on the metal-containing film to form a photoresist top layer film.

[0388] (I-3) After exposing the upper layer of the photoresist to a pattern, develop it with a developer to form a pattern on the upper layer of the photoresist.

[0389] (I-4) Using the patterned resist film as a mask, the pattern is transferred directly or indirectly to the metal-containing film by dry etching.

[0390] (I-5) Using the patterned metal-containing film as a mask, the substrate to be processed is directly or indirectly processed to form a pattern on the substrate.

[0391]

[12] As in

[11] , the pattern forming method wherein at least one organic resist underlayer film is present between the processed substrate and the metal-containing film.

[0392]

[13] The pattern forming method as in

[11] or

[12] , wherein the upper layer of the resist is formed directly on the metal-containing film.

[0393]

[14] A pattern forming method of any one of

[11] to

[13] , wherein, after the step of using the metal-containing film as a mask and processing the film directly beneath the metal-containing film to form a pattern, the metal-containing film is removed by a chemical solution.

[0394]

[15] As in the pattern forming method of

[14] , wherein the chemical solution is a liquid containing hydrogen peroxide and acid, or a liquid containing alkali, hydrogen peroxide and water.

[0395] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any embodiment having a substantially identical structure to the technical concept described in the claims of the present invention and achieving the same effect is covered within the technical scope of the present invention.

[0396] Explanation of reference numerals in the attached figures

[0397] 1: The substrate being processed

[0398] 1a: Pattern (the pattern formed on the substrate being processed)

[0399] 2: Organic resist underlayer film

[0400] 2a: Pattern of the lower layer film of organic photoresist

[0401] 3: Metal-containing membranes

[0402] 3a: Metallic film pattern

[0403] 4: Top layer of resist film

[0404] 4a: Pattern of the upper layer of the resist film

[0405] 5: Mask

Claims

1. A metal-containing film-forming compound, which is (A) a metal-containing film-forming compound, characterized in that: The (A) metal-containing film-forming compound comprises at least one metal atom selected from the group consisting of Ti, Zr, and Hf, and a ligand coordinated to the metal atom. At least one of the ligands is an organic sulfonic acid compound represented by the following formula (s). In the formula, R0 represents a monovalent organic group containing one or more of an unsaturated hydrocarbon group excluding an aromatic ring and an alkoxy group, having 1 to 30 carbon atoms.

2. The metal-containing film-forming compound according to claim 1, wherein, The R0 is a monovalent organic group containing one or more of the following: vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, and alkoxy, having 1 to 30 carbon atoms.

3. The metal-containing film-forming compound according to claim 2, wherein, The R0 is an alkyl group having 2 to 30 carbon atoms or an aryl group having 7 to 30 carbon atoms, selected from one or more functional groups selected from vinyl, allyl, allyloxy, ethynyl, propynyl, propynyloxy, and alkoxy.

4. The metal-containing film-forming compound according to claim 3, wherein, The R0 is an aryl group containing 7 to 30 carbons, selected from at least one of the functional groups selected from vinyl, allyl, allyloxy, ethynyl, propynyl, propynyloxy, and alkoxy.

5. The metal-containing film-forming compound according to claim 1, wherein, The (A) metal-containing film-forming compound also contains ligands from silicon compounds represented by the following general formula (w). In the formula, R A R B and R C It is any organic group selected from the following general formulas (w-1) to (w-3) having any crosslinking group having 2 to 30 carbons, substituted or unsubstituted alkyl groups having 1 to 20 carbons, and aryl groups having 6 to 20 carbons. In general formulas (w-1) to (w-3), R s It is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bonded part.

6. The metal-containing film-forming compound according to claim 1, wherein, The metal-containing film-forming compound (A) is a reaction product of a metal compound represented by formula (a), or a hydrolysate, condensate, or hydrolysate-condensate containing any of the metal compounds represented by formula (a), and a compound containing the structure represented by formula (s). L a MX b (a) In the formula, M is any of Ti, Zr, and Hf, L is a monodentate or polydentate ligand with 1 to 30 carbon atoms, and X is selected from halogen atoms, alkoxy groups, carboxylic acid groups, acyloxy groups, and -NR. 1 R 2 Hydrolyzable groups, R 1 and R 2 Each is an independent hydrogen atom or a monovalent organic group with 1 to 20 carbon atoms, a + b = 2 to 4, where a and b are integers from 0 to 4.

7. The metal-containing film-forming compound according to claim 6, wherein, Equation (a) has the structure of equation (a-1). M(OR 1A )4 (a-1) 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.

8. A metal-containing film forming composition, which functions as a metal-containing film material used in semiconductor manufacturing, characterized in that... It contains (A) a metal-containing film-forming compound according to any one of claims 1 to 7 and (B) an organic solvent.

9. The metal-containing film-forming composition according to claim 8, wherein, The composition further contains one or more of (C) a crosslinking agent, (D) an acid generating agent, and (E) a surfactant.

10. The metal-containing film-forming composition according to claim 8, wherein, The (B) organic solvent contains one or more organic solvents that have a boiling point of 180°C or higher, which are also high-boiling point solvents of (B1).

11. A pattern forming method, characterized in that it forms a pattern on a substrate to be processed. It has the following steps: (I-1) Direct or indirect coating on the substrate being processed After forming the metal-containing film according to claim 8, a heat treatment is performed to form a metal-containing film. (I-2) A photoresist material is used directly or indirectly on the metal-containing film to form a photoresist top layer film. (I-3) After exposing the upper layer of the photoresist to a pattern, develop it with a developer to form a pattern on the upper layer of the photoresist. (I-4) Using the patterned resist film as a mask, the pattern is transferred directly or indirectly to the metal-containing film by dry etching. (I-5) Using the patterned metal-containing film as a mask, the substrate to be processed is directly or indirectly processed to form a pattern on the substrate.

12. The pattern forming method according to claim 11, wherein, The substrate being processed contains at least one organic resist underlayer film between it and the metal-containing film.

13. The pattern forming method according to claim 11, wherein, The upper layer of the resist is formed directly on the metal-containing film.

14. The pattern forming method according to claim 11, wherein, The step includes the step of removing the metal-containing film using a chemical solution after the step of using the metal-containing film as a mask and processing the film directly below the metal-containing film to form a pattern.

15. The pattern forming method according to claim 14, wherein, The chemical solution is a liquid containing hydrogen peroxide and acid, or a liquid containing alkali, hydrogen peroxide and water.

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