Composition for forming metal-containing film and patterning process

Abstract

The objective of this invention is to provide a metal-containing film-forming composition that exhibits superior dry etching resistance and high-level packing / planarization characteristics compared to conventional organic underlayer film materials, and a method for patterning an underlayer film material using this composition. The solution of this invention is a metal-containing film-forming composition comprising (A) a resin, (B) a metal source, and (C) an organic solvent, characterized in that: the (A) resin is a resin free of phenolic hydroxyl groups, and the (B) metal source is a salt of a metal selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi, and a carboxylic acid salt with a carbon number of 1 to 30 and a valence of 1 to 4, or a complex of the metal and a β-diketone.

Description

[Technical Field]

[0001] The present invention relates to a composition for forming a metal-containing film with fine patterning that can be used in the multilayer resist method in the manufacturing process of semiconductor devices, and a patterning method using the composition. [Previous Technology]

[0002] With the increasing integration and speed of LSI, the miniaturization of pattern sizes is rapidly advancing. Lithography, in line with this miniaturization, utilizes shorter wavelengths of light sources and appropriate selection of resist compositions to achieve the formation of fine patterns. At its core is a single-layer positive photoresist composition. This single-layer positive photoresist composition forms a pattern by having a framework in the resist resin that is etch-resistant to dry etching using chlorine-based or fluorine-based gas plasmas, and possessing a switching mechanism such as the dissolution of the exposed area. The pattern is formed by dissolving the exposed area, and the remaining resist pattern is used as an etching mask to perform dry etching on the substrate.

[0003] However, when miniaturization is performed while maintaining the thickness of the photoresist film used, that is, when the pattern width is reduced to a smaller size, the resolution performance of the photoresist film will decrease. Furthermore, if the photoresist film is to be patterned using a developer, the aspect ratio will become too large, resulting in pattern corruption. Therefore, along with the miniaturization of the pattern, the photoresist film is gradually becoming thinner.

[0004] On the other hand, the processing of the substrate typically employs the following method: a patterned photoresist film is formed as an etching mask, and dry etching is used 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 is damaged and breaks down, and the resist pattern cannot be correctly transferred to the substrate. Consequently, with the miniaturization of patterns, the resist composition is increasingly seeking higher dry etching resistance. However, on the other hand, in order to improve resolution, the resin used in the photoresist composition is increasingly seeking resins with low light absorption at the exposure wavelength. Therefore, as the exposure light becomes shorter wavelength, such as i-rays, KrF, and ArF, the resin is also gradually changing to phenolic varnish resins, polyhydroxystyrene, and resins with aliphatic polycyclic skeletons. However, in reality, the etching speed in the dry etching conditions during substrate processing is gradually increasing, and the most recent photoresist compositions with high resolution tend to have weaker etching resistance.

[0005] Considering this situation, it has become necessary to use a photoresist film with thinner etching resistance to dry etch the substrate. Ensuring the quality of materials and processing in this step has gradually become a top priority.

[0006] The multilayer resist method is one of the methods to solve such problems. This method involves placing a resist intermediate film with different etching selectivity than the photoresist film (i.e., the upper resist film) between the upper resist film and the substrate to be processed. After the upper resist film is patterned, the pattern of the upper resist film is used as a dry etching mask, and the pattern is transferred to the resist intermediate film by dry etching. Then, the resist intermediate film is used as a dry etching mask, and the pattern is transferred to the substrate to be processed by dry etching.

[0007] One type of multilayer resist method is the three-layer resist method, which can be implemented using the general resist composition used in the single-layer resist method. This three-layer resist method involves, for example, forming an organic film such as phenolic varnish resin as the lower resist film on a substrate, forming a silicon-containing resist intermediate film on top of it, and forming a conventional organic photoresist film as the upper resist film on top of it. When performing dry etching using fluorine-based gas plasma, the organic resist upper film can achieve a better etch selectivity than the silicon-containing resist intermediate film; therefore, the pattern of the upper resist film can be transferred to the silicon-containing resist intermediate film using dry etching with fluorine-based gas plasma. By this method, even when using resist compositions that are difficult to form patterns with sufficient film thickness for direct processing of the substrate, or resist compositions that do not have sufficient dry etching resistance for substrate processing, patterns can still be transferred onto a silicon-containing resist intermediate film (resistor intermediate film). Then, pattern transfer by dry etching using oxygen-based or hydrogen-based gas plasma is performed, resulting in an organic film (resistor underlayer film) pattern obtained from phenolic varnish resin or similar materials that has sufficient dry etching resistance for substrate processing. Regarding the resist underlayer film described above, numerous examples, such as those described in Patent Document 1, are already known.

[0008] On the other hand, in recent years, the miniaturization of DRAM memory has been accelerating, and the need for further improvements in dry etching resistance and resist underlayer films with excellent embedding and planarization properties is increasing. Regarding coating-type organic underlayer film materials with excellent embedding and planarization properties, such as those described in Patent Document 2, there are concerns about dry etching resistance when considering advanced generation applications, and they are approaching the application limits of conventional coating-type organic underlayer film materials.

[0009] In response to the above-mentioned issues, the development of materials containing metal elements for use in the resist underlayer film has been explored. Patent document 3 reports that materials using Ti compounds exhibit excellent dry etching resistance to CHF3 / CF4 and CO2 / N2 gases.

[0010] On the other hand, regarding the issues of using metal compounds in resist underlayer films, the issue of packing properties can be cited. Although Patent Document 3 does not mention packing properties, generally speaking, metal oxide compounds experience increased thermal shrinkage during baking, and high-temperature baking can lead to significant deterioration in packing properties. Therefore, there are concerns that they are insufficient as resist underlayer film materials requiring high levels of planarization, packing properties, and heat resistance. Patent Documents 4 and 5 report that metal compounds modified with specific ligands have excellent packing properties, but the baking temperature used for the packing property evaluation is a low temperature of 150°C, which is still insufficient as a resist underlayer film requiring heat resistance (e.g., the properties for heat treatment when applied after the resist underlayer film is formed).

[0011] In response, some have proposed compositions for forming metal oxide films by adding high-carbon polymers to metal oxide nanoparticles (Patent Documents 5 and 6). Patent Document 5 reports that by using metal oxide nanoparticles with low thermal shrinkage to metal oxide compounds, the filling characteristics are improved compared to metal oxide compounds. However, the film formed using metal nanoparticles is crystalline, so when nanoparticles are used as the underlayer film material of the resist, there is a concern that the linewidth roughness (LWR) of the pattern will deteriorate when etching the substrate.

[0012] Patent documents 7 and 8 discuss inhibitor materials containing metal salts and organometallic complexes. These materials are designed to promote cross-linking of the inhibitor material; phenolic resins are an example, but the stability of phenolic hydroxyl groups with metal salts and organometallic complexes is problematic. Furthermore, the lower layer film of the inhibitor requires properties such as heat resistance, packing / planarization characteristics, and dry etching resistance, thus requiring a material design different from the above. [Prior Art Documents] [Patent Documents]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 2004-205685 [Patent Document 2] Japanese Patent No. 6714493 [Patent Document 3] Japanese Patent No. 6342998 [Patent Document 4] Japanese Patent No. 5756134 [Patent Document 5] Japanese Patent No. 7008075 [Patent Document 6] Japanese Patent No. 6587516 [Patent Document 7] Japanese Patent No. 5708521 [Patent Document 8] Japanese Patent No. 5708522 [Summary of the Invention]

[0014] [Problem to be Solved by the Invention] In view of the above-mentioned circumstances, the present invention aims to provide a metal-containing film forming composition that exhibits superior dry etching resistance compared to conventional organic underlayer film materials, while also possessing a high level of filling / planarization characteristics, and a method for patterning an underlayer film material using the composition. [Means for Solving the Problem]

[0015] In order to solve the above-mentioned problems, the present invention provides a metal-containing film forming composition comprising (A) a resin, (B) a metal source and (C) an organic solvent, wherein the (A) resin is a resin without phenolic hydroxyl groups, and the (B) metal source is a salt of a metal selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf and Bi and a carboxylic acid with a carbon number of 1 to 30 and a valence of 1 to 4, or a complex of the metal and a β-diketone.

[0016] If the composition for film formation is such a metal-containing material, it can provide a resist underlayer film material with excellent dry etching resistance, low volume shrinkage during baking, and excellent planarization / filling properties even after high-temperature baking. Furthermore, (A) resin does not contain phenolic hydroxyl groups, so it can provide a resist underlayer film material with excellent storage stability.

[0017] Furthermore, it is preferable that the (A) resin contains one or more crosslinking groups selected from substituted or unsubstituted vinyl, allyl, allyloxy, ethynyl, propynyl, propynyloxy, epoxy, and oxy-heterobutyl.

[0018] If it is such a metal-containing film-forming composition, it can provide a resist underlayer film material that can take into account both thermal fluidity and thermosetting properties at a high level, and will exhibit better planarization / filling properties.

[0019] Furthermore, the (A) resin contains an aromatic ring, an alicyclic hydrocarbon, or a heteroaromatic ring, and preferably contains a crosslinking group represented by the following formula (1): [Chemical 1] In the formula, * represents the bonding site with the aromatic ring, alicyclic hydrocarbon, or heteroaromatic ring, RA is a divalent organic group with 1 to 10 carbon atoms, RB is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, RC and RD represent any one of hydrogen atom, hydroxyl group, alkyl group with 1 to 10 carbon atoms, aryl group with 1 to 10 carbon atoms, or alkoxy group with 1 to 10 carbon atoms, and L is a divalent organic group with 1 to 10 carbon atoms.

[0020] If it is such a metal-containing film forming composition, it can provide a resist underlayer film material that can take into account both thermal fluidity and thermosetting properties at a high level, and will exhibit better planarization / filling properties.

[0021] The metal source of (B) is preferably a salt of the metal and a carboxylic acid with a carbon number of 1 to 30 and a valence of 1 to 4.

[0022] If the composition for forming a metal film contains such a metal source (B), a resist underlayer film with better dry etching resistance can be formed. Furthermore, this is preferable from the perspective of solvent solubility and the availability of raw materials.

[0023] Furthermore, the structure represented by the following formula (B-1) of the (B) metal source system is preferred. [Chemical 2] In the formula, M is selected from any of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi, R1 is a monovalent organic group with 1 to 30 carbon atoms, and n is an integer from 1 to 4.

[0024] If the composition for forming a metal film contains such a metal source (B), a resist underlayer film with excellent dry etching resistance can be reliably formed. Furthermore, this is preferable from the perspective of solvent solubility and the availability of raw materials.

[0025] Also, the metal system Sn of the (B) metal source.

[0026] If it is a metal-containing film-forming composition containing such a (B) metal source, it is preferable to obtain a resist lower film-forming composition that can help improve sensitivity while maintaining the LWR of the upper resist.

[0027] Furthermore, it is preferable that the aforementioned (A) resin has at least one constituent unit represented by the following general formulas (G-1) to (G-5). [Chemical Engineering 3] In the formula, W1 and W2 are each independently a benzene ring or a naphthalene ring. The hydrogen atoms in the benzene ring and the naphthalene ring can also be replaced by hydrocarbon groups with 1 to 6 carbon atoms. Ra is represented by the following general formula (Z-1), Y is represented by the following general formula (Z-2), n1 is 0 or 1, n2 is 1 or 2, and V independently represents a hydrogen atom or a linking part. [Chemical Engineering 4] In the formula, Z1 is represented by the following general formula (Z-3), Ra is represented by the following general formula (Z-1), n4 is 0 or 1, n5 is 1 or 2, and V independently represents a hydrogen atom or a linking part. [Chemical Engineering 5] In the formula, * represents the bonding site with an oxygen atom. RB is a divalent organic group with 1 to 10 carbon atoms, and RA is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms. [Chemical Engineering 6] In the formula, * represents an atomic bond. [Chemical Engineering 7] In the formula, * represents an atomic bond. W1, W2, Y, and n1 are the same as above. [Chemical Engineering 8] In formula, m3 and m4 represent 1 or 2, Z is a single bond or any of the structures represented by the following general formula (Z-4), Rx is any of the structures represented by the following general formula (Z-5), [Chemical Engineering 9] In formula, * represents an atomic bond, l represents an integer from 0 to 3, Ra~Rf each independently represents a hydrogen atom or an alkyl, phenyl, or phenylethyl group with 1 to 10 carbon atoms that can also be substituted with fluorine, Ra and Rb can also be bonded to form a cyclic compound, [Chemical Engineering 10] In formula, * represents the bonding site with an aromatic ring, Q1 is a straight-chain saturated hydrocarbon group of 1 to 30, or a structure represented by the following general formula (Z-6) [Chem. 11] In the formula, * indicates the bonding site with the carbonyl group, Ra is the general formula (Z-1), Rj represents a straight-chain or branched hydrocarbon group, halogen atom, nitro group, amino group, nitrile group, alkoxy carbonyl group with 1 to 10 carbons, or alkoxy group with 1 to 10 carbons, h3 and h4 represent the number of substituents on the aromatic ring, each representing an integer from 0 to 7, except that h3+h4 is 0 to 7, and h5 represents 0 to 2. [Chem. 12] In the formula, R1 is a saturated monovalent organogroup with 1 to 30 carbons or an unsaturated monovalent organogroup with 2 to 30 carbons, X is a divalent organogroup with 1 to 30 carbons, Ra is the general formula (Z-1), p is an integer from 0 to 5, q1 is an integer from 1 to 6, p+q1 is an integer from 1 to 6, and q2 is 0 or 1.

[0028] If the composition for forming a film containing metal is such, the thermal fluidity of the composition for forming a film containing metal will be further improved, and the filling and planarization characteristics of substrates with uneven surfaces can be improved. Furthermore, when used directly below the upper resist film, a lower resist film with excellent adhesion to the upper resist film can be formed.

[0029] Furthermore, the composition may further include one or more of (D) a crosslinking agent, (E) an acid generating agent, (F) a surfactant, and (G) a pigment.

[0030] The metal-containing film-forming composition of the present invention may contain such components as needed.

[0031] It is preferable that the (C) organic solvent is 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 ((C') high-boiling solvents).

[0032] Since the addition of a high-boiling-point solvent to the above-mentioned metal-containing film-forming composition provides fluidity, the generation of coating defects caused by the drying of the metal-containing film-forming composition can be suppressed.

[0033] The present invention also provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed, comprising the following steps: (I-1) coating the above-mentioned metal-containing film forming composition on the substrate to be processed, and forming a metal-containing film by heat treatment; (I-2) forming a resist upper layer film on the metal-containing film using a photoresist material; (I-3) exposing the resist upper layer film to a pattern, and developing it with a developer to form a pattern on the resist upper layer film; (I-4) using the resist upper layer film with the pattern formed as a mask, transferring the pattern onto the metal-containing film by dry etching; and (I-5) using the metal-containing film with the pattern formed as a mask, processing the substrate to form a pattern on the substrate to be processed.

[0034] By means of the above-mentioned patterning method of two layers of resist treatment, fine patterns can be formed on the workpiece (workpiece substrate).

[0035] The present invention also provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed, comprising the following steps: (II-1) coating the above-mentioned metal-containing film forming composition on the substrate to be processed, and then forming a metal-containing film by heat treatment; (II-2) forming a silicon resist-containing intermediate film on the metal-containing film; (II-3) forming a resist upper layer film on the silicon resist-containing intermediate film using a photoresist material; (II-4) exposing the resist upper layer film to a pattern, and then developing it with a developer to form a pattern on the resist upper layer film; (II-5) using the patterned resist upper layer film as a mask, and transferring the pattern onto the silicon resist-containing intermediate film by dry etching. (II-6) Using the silicon resist intermediate film with the transferred pattern as a mask, the pattern is transferred onto the metal film by dry etching, and (II-7) Using the metal film with the formed pattern as a mask, the substrate to be processed is processed to form a pattern on the substrate.

[0036] The pattern forming method using the above-mentioned three-layer resist treatment can form fine patterns on the workpiece with high precision.

[0037] The present invention also provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed, comprising the following steps: (III-1) coating the above-mentioned metal-containing film forming composition on the substrate to be processed, and then forming a metal-containing film by heat treatment; (III-2) forming an inorganic hard mask intermediate film selected from silicon oxide film, silicon nitride film, and silicon oxynitride film on the metal-containing film; (III-3) forming an organic film on the inorganic hard mask intermediate film; (III-4) forming a resist upper layer film on the organic film using a photoresist material; (III-5) exposing the resist upper layer film to a pattern, and then developing it with a developer to form a pattern on the resist upper layer film; (III-6) using the patterned resist upper layer film as a mask, and transferring the pattern to the organic film and the inorganic hard mask intermediate film by dry etching. (III-7) Using the inorganic hard mask intermediate film with the transferred pattern as a mask, the pattern is transferred onto the metal-containing film by dry etching, and (III-8) Using the metal-containing film with the formed pattern as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed.

[0038] The pattern forming method using the above-mentioned four-layer resist treatment can form fine patterns on the workpiece with high precision.

[0039] The present invention also provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed, comprising the following steps: (IV-1) coating the above-mentioned metal-containing film forming composition on the substrate to be processed, and then forming a metal-containing film by heat treatment; (IV-2) forming an organic intermediate film on the metal-containing film; (IV-3) forming a silicon resist-containing intermediate film, or a combination of an inorganic hard mask intermediate film selected from silicon oxide film, silicon nitride film, and silicon oxynitride film and an organic thin film, on the organic intermediate film; (IV-4) forming a resist upper layer film using a photoresist material on the silicon resist-containing intermediate film or the organic thin film; (IV-5) after exposing the resist upper layer film to a pattern, developing it with a developer to form a pattern on the resist upper layer film. (IV-6) Using the patterned resist top film as a mask, the pattern is transferred to the silicon resist intermediate film or the organic film and the inorganic hard mask intermediate film by dry etching. (IV-7) Using the patterned silicon resist intermediate film or the inorganic hard mask intermediate film as a mask, the pattern is transferred to the organic intermediate film by dry etching. (IV-8) Using the organic intermediate film as a mask, the pattern is transferred to the metal film by dry etching. (IV-9) Using the patterned metal film as a mask, the substrate is processed to form a pattern on the substrate.

[0040] By means of the above-mentioned pattern forming method of multilayer resist treatment, fine patterns can be formed on the workpiece with high precision.

[0041] The present invention also provides a pattern forming method, which is a method for forming a tone-reversed pattern on a substrate to be processed, comprising the following steps: (V-1) forming a lower resist film on the substrate to be processed; (V-2) forming a resist intermediate film or a combination of an inorganic hard mask intermediate film and an organic thin film selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film on the lower resist film; (V-3) forming a resist upper film using a photoresist material on the resist intermediate film or the combination of inorganic hard mask intermediate film and organic thin film; (V-4) exposing the resist upper film to a pattern and developing it with a developer to form a pattern on the resist upper film; (V-5) using the resist upper film with the pattern formed as a mask, transferring the pattern onto the resist intermediate film or the organic thin film and the inorganic hard mask intermediate film by dry etching. (V-6) Using the resist interlayer film or inorganic hard mask interlayer film with the transferred pattern as a mask, the pattern is transferred onto the resist underlayer film using dry etching. (V-7) After coating the resist underlayer film with the pattern formed with the aforementioned metal-containing film-forming composition, the metal-containing film is coated by heat treatment, and the spaces between the patterns on the resist underlayer film are filled with the metal-containing film. (V-8) The metal-containing film covering the resist underlayer film with the pattern formed is chemically stripped or dry-etched to expose the top surface of the resist underlayer film with the pattern formed. (V-9) The resist interlayer film or hard mask interlayer film remaining on the top surface of the resist underlayer film is removed by dry etching. (V-10) The resist underlayer film with the exposed pattern is removed by dry etching to form a reversed pattern of the original pattern composed of a metal-containing film. (V-11) The metal-containing film with the inverted pattern is used as a mask to process the substrate to form an inverted pattern on the substrate.

[0042] By means of the pattern forming method of the above-mentioned inversion process, fine patterns can be formed on the workpiece with higher precision.

[0043] Furthermore, in this step (I-3), it is preferable to use EUV light to expose the pattern.

[0044] Furthermore, in this step (II-4), it is preferable to use EUV light to expose the pattern.

[0045] Furthermore, in this step (III-5), it is preferable to use EUV light to expose the pattern.

[0046] Furthermore, in this step (IV-5), it is preferable to use EUV light to expose the pattern.

[0047] Furthermore, in this step (V-4), it is preferable to use EUV light to expose the pattern.

[0048] The metal-containing film-forming composition of the present invention contains metal atoms with high light absorption, thus enabling the formation of a lower resist film in EUV lithography that helps improve sensitivity while maintaining the LWR of the upper resist layer. [Effects of the Invention]

[0049] If it is such a metal-containing film-forming composition, then by heat treatment, the metal salt structure will decompose and the metal ions will be released to form a metal oxide, thus providing a resist lower layer film with a high metal content. Furthermore, since it is a mixture with resin (A), it provides a resist lower layer film material with low volume shrinkage during baking and excellent planarization / filling properties even after high-temperature baking. Moreover, the aforementioned resin (A) does not contain phenolic hydroxyl groups, thus providing a metal-containing film-forming composition with excellent stability.

[0050] Furthermore, regarding the resist lower layer film formed using the metal-containing film-forming composition of the present invention, the film contains a large number of metal atoms with high light absorption, thus exhibiting a characteristic of enhanced sensitivity due to secondary electrons generated during exposure in EUV lithography. Moreover, the large atomic mass of the aforementioned metal atoms results in a high degree of suppression of acid diffusion from the upper resist layer to the resist lower layer film, and simultaneously maintains the LWR performance inherent in the upper resist layer film while achieving high sensitivity.

[0051] Furthermore, the resist underlayer film exhibits high etch selectivity with organic materials, thus enabling the formed photoresist pattern to be sequentially transferred to a metal-containing resist underlayer film, an organic underlayer film, or a CVD organic hard mask using dry etching. In particular, with the ongoing miniaturization of semiconductor device manufacturing processes in recent years, there is a tendency to thin the photoresist film to prevent pattern collapse after development, making pattern transfer to the resist underlayer film increasingly difficult. However, by using the metal-containing film-forming composition of the present invention, even when the thin photoresist film is used as an etching mask, deformation of the photoresist pattern during dry etching can be suppressed, and the pattern can be transferred to the substrate with high precision.

Implementation Method

[0053] As described above, in the micro-patterning process using the multilayer resist method, it is necessary to develop a metal-containing film forming composition with excellent filling and flatness for forming a resist underlayer film that can transfer resist patterns onto the substrate being processed with higher precision, a metal-containing film forming compound useful to the composition, and a pattern forming method using the aforementioned composition.

[0054] The inventors of this case focused on metal materials that exhibit excellent etching resistance compared to conventional resist underlayer film materials, and conducted repeated in-depth research. On the other hand, conventional metal compounds used for forming resist underlayer films lack heat resistance and undergo severe volume shrinkage during baking, making it difficult to fill and planarize the height differences of the processed substrate after high-temperature baking.

[0055] The inventors of this invention believe that if the metal is selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi and a salt of a carboxylic acid with 1 to 30 carbon atoms in a 1 to 4 valence, or a complex of the aforementioned metals and β-diketones, the volume shrinkage during baking is small. By combining with resin, even after high-temperature baking, no voids will be generated, thus filling the height difference of the processed substrate. Furthermore, the inventors of this invention have discovered that if the resin has a structure without phenolic hydroxyl groups, it can provide a composition for forming metal-containing films with excellent preservation stability, thereby completing this invention.

[0056] That is, the present invention is a metal-containing film forming composition comprising (A) a resin, (B) a metal source, and (C) an organic solvent. The aforementioned (A) resin is a resin without phenolic hydroxyl groups, and the aforementioned (B) metal source is a salt of a metal selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi with a carboxylic acid with a carbon number of 1 to 30 and a valence of 1 to 4, or a complex of the aforementioned metal with a β-diketone.

[0057] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0058] <Metal-containing film forming composition> The metal-containing film forming composition of the present invention comprises (A) a resin, (B) a metal source, and (C) an organic solvent. The resin (A) is a resin without phenolic hydroxyl groups, and the metal source (B) is a salt of a metal selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi with a carboxylic acid with a carbon number of 1 to 30 and a valence of 1 to 4, or a complex of the aforementioned metal with a β-diketone.

[0059] <(A) Resin> The (A) resin contained in the metal-containing film-forming composition of the present invention is a resin that does not contain phenolic hydroxyl groups.

[0060] If it is a metal-containing film-forming composition containing such a resin, a metal-containing film-forming composition with excellent storage stability can be provided.

[0061] Furthermore, it is preferable that the aforementioned (A) resin contains a crosslinking group selected from one or more of substituted or unsubstituted vinyl, allyl, allyloxy, ethynyl, propargyl, propargyloxy, epoxy, and oxy-containing heterocyclic butyl.

[0062] By including such crosslinking groups, the thermosetting properties of the resin are improved. When used in metal-containing film-forming compositions, it can provide a resistive underlayer film material that can reduce volume shrinkage during high-temperature baking and has excellent filling / planarization characteristics.

[0063] The aforementioned (A) resin contains an aromatic ring, an alicyclic hydrocarbon, or a heteroaromatic ring, and preferably contains a crosslinking group represented by the following formula (1). [Chemical 13] In the formula, * represents the bonding site with the aromatic ring, alicyclic hydrocarbon, or heteroaromatic ring, RA is a divalent organic group with 1 to 10 carbon atoms, RB is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, RC and RD represent any one of hydrogen atom, hydroxyl group, alkyl group with 1 to 10 carbon atoms, aryl group with 1 to 10 carbon atoms, or alkoxy group with 1 to 10 carbon atoms, and L is a divalent organic group with 1 to 10 carbon atoms.

[0064] In the above formula, RA refers to a divalent organogroup with 1 to 10 carbon atoms, preferably an alkyl group with 1 to 10 carbon atoms, and even more preferably a methylene group. RB refers to a hydrogen atom or a monovalent organogroup with 1 to 10 carbon atoms; considering thermosetting properties and flowability, a hydrogen atom or a structure represented by the following formula (RB-1) is preferred. RC and RD refer to any one of hydrogen atom, hydroxyl group, alkyl group with 1 to 10 carbon atoms, aryl group with 1 to 10 carbon atoms, or alkoxy group with 1 to 10 carbon atoms, preferably an alkyl group with 1 to 10 carbon atoms, and even more preferably a methyl or ethyl group. L refers to a divalent organogroup with 1 to 10 carbon atoms, and a structure represented by the following formula (L-1) is preferred.

[0065] [Chemical 14] In the above formula, p is an integer from 0 to 9, and * is the bonding location.

[0066] [Chemical 15] In the above formula, *1 represents the bonding site with the aromatic ring, alicyclic hydrocarbon, or heteroaromatic ring, and *2 represents the bonding site with the carbon atoms of the epoxy ring and the oxobutane ring.

[0067] By including aromatic rings, alicyclic hydrocarbons, or heteroaromatic rings in resin (A), the heat resistance of the resin is improved. When used in metal-containing film-forming compositions, it can provide a resistive underlayer film material that reduces volume shrinkage during high-temperature baking and has excellent filling / planarization characteristics. Furthermore, by including the aforementioned crosslinking groups, the thermosetting properties of the resin are improved. When used in metal-containing film-forming compositions, it can provide a resistive underlayer film material that further reduces volume shrinkage during high-temperature baking and has excellent filling / planarization characteristics.

[0068] The aromatic ring, alicyclic hydrocarbon, or heteroaromatic ring of the aforementioned resin (A) can be exemplified by the following structure. [Chemical 16] The hydrogen atom in the above formula can also be replaced by a monovalent organic group having 1 to 20 carbon atoms.

[0069] Regarding the resin (A) described above, the ratio of the weight-average molecular weight Mw to the number-average molecular weight Mn of polystyrene obtained by gel permeation chromatography, Mw / Mn (i.e., dispersity), is preferably in the range of 1.00 ≤ Mw / Mn ≤ 1.25, and more preferably 1.00 ≤ Mw / Mn ≤ 1.10. By definition, if it is a monomolecular compound, Mw / Mn is 1.00, but due to the separation properties of GPC, the measured value sometimes exceeds 1.00. Generally speaking, it is very difficult for polymers with repeating units to approach Mw / Mn = 1.00 unless a special polymerization method is used, and they will have a distribution of Mw and a value of Mw / Mn exceeding 1. In order to distinguish monomolecular compounds from polymers, the present invention defines 1.00 ≤ Mw / Mn ≤ 1.10 as an indicator of monomolecularity.

[0070] If a compound has such a range of dispersion, it will have better thermal fluidity in metal-containing film-forming compositions. Therefore, when used in metal-containing film-forming compositions, it can provide a resist underlayer film material with excellent packing / planarization characteristics.

[0071] Regarding the above-mentioned resin (A), it is preferable to use a polymer with a weight average molecular weight of 1,000 to 12,000 based on polystyrene obtained by gel permeation chromatography, and it is preferable to have a Mw of 2,000 to 10,000.

[0072] Such a molecular weight range ensures solubility in organic solvents and suppresses sublimation during baking. Furthermore, it exhibits good thermal fluidity in metal-containing film-forming compositions, thus providing a resist underlayer film material with excellent packing / planarization characteristics when used in metal-containing film-forming compositions.

[0073] The aforementioned resin (A) is preferably having at least one constituent unit represented by the following general formulas (G-1) to (G-5).

[0074] (Structural units: G-1, G-2, and G-3) In the formula, W1 and W2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the benzene ring and naphthalene ring may be substituted by a hydrocarbon group having 1 to 6 carbon atoms. Ra is the following general formula (Z-1), and Y is a group represented by the following general formula (Z-2). n1 is 0 or 1, n2 is 1 or 2, and V each independently represents a hydrogen atom or a linking portion. In the formula, Z1 is a group represented by the following general formula (Z-3), Ra is the following general formula (Z-1), n4 is 0 or 1, n5 is 1 or 2, and V each independently represents a hydrogen atom or a linking portion. In the formula, * represents the bonding site to the oxygen atom, RB is a divalent organic group having 1 to 10 carbon atoms, and RA is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. * represents an atomic bond. In the formula, W1, W2, Y, and n1 are the same as described above.

[0075] For a resin having the structural units represented by the above general formulas (G-1), (G-2), and (G-3), since a condensed carbocyclic ring with a high carbon density containing a cardo structure is introduced, a resist underlayer film excellent in dry etching resistance and heat resistance can be formed.

[0076] In the above general formulas (G-1), (G-2), and (G-3), the above Ra is the above general formula (Z-1), and the structure of the above general formula (Z-1) is preferably the following general formula (2-A).

[0077] [Chemical formula 22] * represents the bonding part to the oxygen atom.

[0078] Since the organic groups represented by the above general formulas (G-1), (G-2), and (G-3) are the organic groups represented by the above general formula (Z-1), especially the organic groups represented by the above general formula (2-A), the thermal fluidity can be further improved, and a resist underlayer film excellent in filling properties and planarization characteristics can be formed.

[0079] For a resin having the structural units represented by the above general formulas (G-1), (G-2), and (G-3), due to the action of the cardo structure introduced into the molecule, the intermolecular interaction is relaxed and the solubility in an organic solvent is provided, so the film-forming property during the formation of a coating film is improved. Also, since multiple condensed carbocyclic rings with a high carbon density are introduced, a resist underlayer film excellent in heat resistance and dry etching resistance can be formed.

[0080] The resin having the structural units represented by the above general formulas (G-1), (G-2), and (G-3) may be a compound represented by the following general formula (g-1) and / or (g-2) and / or (g-3).

[0081] [Chemical 23] In the above general formulas (g-1) and (g-2), W1, W2, Ra, Y, n1, and n2 are the same as those mentioned above.

[0082] [Chemical 24] In the above general formula (g-3), Z1, Ra, n4, and n5 are the same as those mentioned above.

[0083] Specifically, for example of a resin having constituent units represented by the above general formulas (g-1), (g-2) and (g-3), the following compounds can be specifically exemplified but are not limited to them.

[0084] [Chemical 25]

[0085] For the above-mentioned resins (g-1), (g-2) and (g-3), the ratio of the weight average molecular weight Mw to the number average molecular weight Mn of polystyrene obtained by gel permeation chromatography, Mw / Mn (i.e., dispersity), is preferably in the range of 1.00 ≤ Mw / Mn ≤ 1.25, and more preferably 1.00 ≤ Mw / Mn ≤ 1.10.

[0086] If the compound has such a range of dispersion, it will be a composition for forming metal films with better thermal fluidity.

[0087] A resin having constituent units represented by the above general formulas (G-1), (G-2) and (G-3) may be a polymer having repeating units represented by the following general formulas (g-4) and / or (g-5) and / or (g-6).

[0088] [Chemical 26] In the above general formulas (g-4) and (g-5), W1, W2, Ra, Y, n1, and n2 are the same as those mentioned above, and L are divalent organic groups with 1 to 40 carbon atoms.

[0089] [Chemical 27] In the above general formula (g-6), Z1, Ra, n4, and n5 are the same as those mentioned above, and L are divalent organic groups with 1 to 40 carbon atoms.

[0090] These are polymers obtained using compounds represented by the above general formulas (g-1), (g-2) and (g-3). Because of the use of the aforementioned compounds, they have excellent dry etching resistance and heat resistance. Furthermore, since they are polymers with repeating units rather than monomers, they have less gas release components. Also, since they are polymers with a molecular weight distribution, their crystallinity is mitigated, and improved film-forming properties can be expected.

[0091] refers to the L-series divalent organic group with 1 to 40 carbon atoms that forms the linking group of the repeating unit of the above general formulas (g-4), (g-5) and (g-6), and the following are examples.

[0092] [Chemical 28]

[0093] Furthermore, the linker group L of the above polymer should preferably be the following general formula (10). [Chemical 29] In the above general formula (10), R1 is an organic group containing an aromatic ring with 1 to 20 hydrogen atoms or carbon atoms, and the dashed line represents an atomic bond.

[0094] Specifically, the following examples can be given for the above general formula (10). Among the following, considering the ease of obtaining the raw materials, it is preferable that the methylene group, i.e., R1, is a hydrogen atom.

[0095] [Chemical 30]

[0096] Furthermore, the weight-average molecular weight Mw of polystyrene obtained by gel permeation chromatography of polymers having repeating structural units represented by the above general formulas (g-4), (g-5) and (g-6) is preferably 1,000 to 12,000, and more preferably 2,000 to 10,000.

[0097] If the molecular weight is within such a range, solubility in organic solvents can be ensured, and sublimation products generated during baking can be suppressed. Furthermore, it results in a composition for forming metal-containing films with good thermal fluidity.

[0098] Resins containing constituent units represented by the above general formulas (G-1), (G-2), and (G-3) have high carbon density due to their skeletal structure containing a caloric structure. Therefore, metal-containing film-forming compositions containing these compounds exhibit high dry etching resistance and excellent heat resistance. Furthermore, the presence of an organic group represented by the above general formula (G-1) which contributes to improved thermal fluidity allows for the formation of a resist underlayer film with excellent filling and planarization properties. When compounds with structures represented by the above general formulas (g-1), (g-2), and (g-3) are used, the thermal fluidity of the metal-containing film-forming composition is even better. On the other hand, polymers containing constituent units with structures represented by the above general formulas (g-4), (g-5), and (g-6) can suppress the generation of sublimation products during baking, providing metal-containing film-forming compositions with excellent film thickness uniformity. By mixing compounds with structures represented by the above general formulas (g-1), (g-2) and (g-3) and polymers containing constituent units represented by the above general formulas (g-4), (g-5) and (g-6), it is possible to provide metal-containing film-forming compositions that meet the desired properties.

[0099] (Constructing unit: G-4) [Chemical 31] In the formula, m3 and m4 represent 1 or 2, Z is a single bond or any of the structures represented by the following general formula (Z-4). Rx is any of the structures represented by the following general formula (Z-5). [Chemical 32] In the formula, * represents an atomic bond, l represents an integer from 0 to 3, Ra~Rf each independently represents a hydrogen atom or an alkyl, phenyl, or phenylethyl group with 1 to 10 carbon atoms that can be substituted with fluorine, and Ra and Rb can also be bonded to form a cyclic compound. [Chemical 33] In the formula, * represents the bonding site with an aromatic ring, Q1 is a straight-chain saturated hydrocarbon group of 1 to 30, or a structure represented by the following general formula (Z-6). [Chem. 34] In the formula, * indicates the bonding site with the carbonyl group, Ra is the aforementioned general formula (Z-1), and Rj represents a straight-chain or branched hydrocarbon group, halogen atom, nitro group, amino group, nitrile group, alkoxy carbonyl group with 1 to 10 carbon atoms, or alkoxy group with 1 to 10 carbon atoms. h3 and h4 represent the number of substituents on the aromatic ring, respectively representing integers from 0 to 7. However, h3+h4 is 0 to 7. h5 represents 0 to 2.

[0100] Considering dry etching resistance and heat resistance, in the above general formula (G-4), the Z-series single bond or any of the structures represented by the following formula (4A) is preferred. [Chemical 35] In the formula, * represents an atomic bond, and l is the same as in the above formula (Z-4).

[0101] In the above general formula (Z-5), * indicates the bonding site with the aromatic ring. Q1 is a straight-chain saturated hydrocarbon group with 1 to 30 carbon atoms, or the structure represented by the following general formula (Z-6). When Q1 represents a straight-chain hydrocarbon group with 1 to 30 carbon atoms, the methylene group constituting Q1 can also be replaced by an oxygen atom or a carbonyl group. Considering the dry etching resistance and heat resistance, Q1 should preferably be the structure represented by the above general formula (Z-6).

[0102] The above general formula (G-4) can improve thermal fluidity by having an organic group represented by the above general formula (Z-1), especially an organic group represented by the above general formula (2-A).

[0103] Compounds containing the constituent units represented by the above general formula (G-4) have a high carbon density due to their structure of connecting aromatic rings with single bonds or general formula (Z-4). Therefore, metal-containing film-forming compositions containing such compounds exhibit high dry etching resistance and excellent heat resistance. Furthermore, the linker Z, as shown in formula (Z-4), can be selected from various linkers to meet the desired performance requirements. In particular, for Z, by incorporating the structure represented by formula (4A), film-forming properties can be maintained while providing heat resistance / etch resistance. Moreover, having a highly flexible end portion Rx, a thick resist lower layer film can be formed without defects such as cracks, regardless of whether it contains a rigid aromatic ring structure. Furthermore, the end portion Rx contains an end group Q1 that provides thermal fluidity. For the end group Q1, a flexible hydrocarbon structure that helps improve thermal fluidity and a rigid aromatic ring structure that helps with etching resistance and heat resistance can be incorporated in any proportion to meet the desired performance requirements. As mentioned above, metal-containing film-forming compositions using these compounds can achieve a high level of film-forming properties and heat / etch resistance, and can form thick films with the desired characteristics.

[0104] (Constituting unit: G-5) [Chemical 36] In the formula, R1 refers to saturated monovalent organic groups with 1 to 30 carbons or unsaturated monovalent organic groups with 2 to 30 carbons, X refers to divalent organic groups with 1 to 30 carbons, Ra refers to the aforementioned general formula (Z-1), p refers to integers from 0 to 5, q1 refers to integers from 1 to 6, p+q1 refers to integers from 1 to 6, and q2 refers to 0 or 1.

[0105] In the above general formula (G-5), for example, the divalent organic group with 1 to 30 carbon atoms represented by X can be exemplified by methylene, ethanediyl, propanediyl, butanediyl, pentanediyl, hexanediyl, octanediyl, decanediyl, etc., as well as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, cyclohexanediyl, cycloheptanediyl, cyclooctanediyl, cyclodecanediyl, methylcyclohexanediyl, ethylcyclohexanediyl, etc. Monocyclic cycloalkane dimethyl groups such as alkyldiyl, bicyclic [2.2.1]heptanediyl, bicyclic [2.2.2]octanediyl, tricyclic [5.2.1.02,6]decanediyl (dicyclopentyl), tricyclic [3.3.1.13,7]decanediyl, tetracyclic [6.2.1.13,6.02,7]dodecanediyl, adamantanediyl, and other polycyclic cycloalkane dimethyl groups, as well as aromatic dimethyl groups such as phenyl and naphthyl.

[0106] X can also be an alkane dieoxy group or a cycloalkane dieoxy group. For example, a group combining an alkane dieoxy group and an oxygen atom can be listed as an example of an alkane dieoxy group. Similarly, a group combining an cycloalkane dieoxy group and an oxygen atom can be listed as an example of an cycloalkane dieoxy group.

[0107] Some or all of the hydrogen atoms in the above-mentioned alkane dimethyl, cycloalkane dimethyl, alkane dimethyloxy, cycloalkane dimethyloxy and aromatic dimethyl groups may also be replaced. As for the substituents, examples of substituents that may also be present in the organic group represented by Ra above can be listed.

[0108] As for the organic group represented by X above, the following groups can be listed. [Chemical 37] In the above formula, * represents an atomic bond.

[0109] Regarding X above, from the perspective of obtaining raw materials, methylene is a preferred option.

[0110] Specifically, the following can be exemplified as to a resin having the structural unit represented by the above general formula (G-5).

[0111] [Chemistry 38]

[0112] [Chemical 39] In the above formula, Ra is the same as described above.

[0113] Polymers containing the constituent units represented by the above general formula (G-5) have a structure in which aromatic rings are linked by organic groups (X), resulting in high carbon density. Metal-containing film-forming compositions containing such resins exhibit high dry etching resistance and excellent heat resistance, thus enabling the formation of a resist underlayer film with low sublimation. Furthermore, the organic groups in the structure represented by the above general formula (Z-1), which contributes to improved thermal fluidity, are directly bonded to the aromatic rings of the parent structure of the resin via oxygen atoms. Therefore, metal-containing film-forming compositions using such polymers can achieve a high level of balance between film-forming properties and heat / etch resistance. Moreover, the aromatic ring structure of the parent structure is not overly rigid, forming a repeating structure of organic groups (X) that separate the linking groups, thus enabling the formation of a thick resist underlayer film without defects such as cracks. As mentioned above, using metal-containing film-forming compositions of such polymers can achieve a high level of film-forming properties and heat / etch resistance, and can form thick films that meet the required characteristics.

[0114] In the metal-containing film-forming composition of the present invention, the amount of (A) resin is not particularly limited, for example, it is 0.1 to 50 parts by mass relative to 100 parts by mass of (C) organic solvent described later, preferably 1 to 20 parts by mass, and more preferably 2 to 10 parts by mass.

[0115] <(B) Metal Source> The (B) metal source contained in the metal-containing film-forming composition of the present invention is a salt of a metal selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi and a carboxylic acid with a carbon number of 1 to 30 and a valence of 1 to 4, or a complex of the aforementioned metal and a β-diketone.

[0116] The preferred carboxylate can be exemplified as follows. [Chemical 40] In the formula, R1 is the same or different hydrogen atoms, carbon number 1 to 30, preferably a straight-chain, branched or cyclic alkyl group with carbon number 1 to 20, carbon number 2 to 30, preferably an alkenyl group with carbon number 2 to 20, carbon number 2 to 30, preferably an alkynyl group with carbon number 2 to 20, or carbon number 6 to 30, preferably an aryl group with carbon number 6 to 20. These may also have hydroxyl, ether, ester, amino, amide, sulfonate, halogen, cyano, nitro, carbonate, carbamate, thiol, thioether, thionyl, or heteroaromatic rings. R2 is a single bond, or a linear, branched, or cyclic alkyl, alkenyl, or ynyl group with 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms, or an aryl group with 6 to 30 carbon atoms, preferably 6 to 20 carbon atoms. These may also have hydroxyl, ether, ester, amino, amide, sulfonate, halogen, cyano, nitro, carbonate, carbamate, thiol, thioether, thionyl, or heteroaromatic rings. R3 is a group obtained by removing one hydrogen atom from the aforementioned alkyl, aryl, alkenyl, or ynyl group of R2. R4 is a group obtained by removing two hydrogen atoms from the aforementioned alkyl, aryl, alkenyl, or ynyl group of R2.

[0117] The carboxylic acid ion used to form the carboxylate salt in the above general formula can be specifically exemplified as follows.

[0118] [Chemistry 41]

[0119] [Chemistry 42]

[0120] [Chemistry 43]

[0121] [Chemistry 44]

[0122] [Chemistry 45]

[0123] [Chemistry 46]

[0124] [Chemistry 47]

[0125] [Chemistry 48]

[0126] [Chemistry 49]

[0127] [Transformation 50]

[0128] [Chemistry 51]

[0129] Regarding the carboxylic acid ions used to form the aforementioned carboxylate salts, it is preferable that the carboxylic acid has more carbon atoms, making it easier to dissolve in organic solvents. Furthermore, if the carboxylic acid does not have a high number of carbon atoms, the amount of gas release components during spin-coating of metal-containing film-forming compositions will be less, the shrinkage during the formation of inhibitor films will be less, and the packing properties will be better. Considering the above points, it is preferable that the carboxylic acid ion is a straight-chain or branched alkyl group with 3 to 10 carbon atoms.

[0130] Examples of preferred β-diketone complexes include the following.

[0131] [Chemical 52] In the formula, R1 and R2 are the same or different linear, branched or cyclic alkyl groups with 1 to 20 carbon atoms, alkenyl groups with 2 to 20 carbon atoms, alkynyl groups with 2 to 20 carbon atoms, or aryl groups with 6 to 20 carbon atoms. They may also have hydroxyl, alkoxy, ether, ester, amino, amide, sulfonate, halogen, cyano, nitro, carbonate, carbamate, thiol, thioether, thionyl, or heteroaromatic rings.

[0132] The β-diketones in the above general formula are substituted or unsubstituted acetones, specifically exemplified as follows.

[0133] [Chemical 53]

[0134] [Chemical 54]

[0135] [Transformation 55]

[0136] [Transformation 56]

[0137] [Chemical 57]

[0138] [Transformation 58]

[0139] Generally, β-diketones have the same R1 and R2, but they can also be different as described in Japanese Patent Application Publication No. 2004-175755. R1 and R2 are most commonly methyl acetones, but they have the disadvantage of lacking solubility in organic solvents. It is preferable that the total number of carbons in R1 and R2 is 3 or more, and even more preferably 4 or more.

[0140] It is preferable that the hydrogen atoms of acetone are substituted, and the more carbon atoms of the substituent, the easier it is to dissolve in organic solvents. On the other hand, if the number of carbon atoms of the substituent is not too high, the shrinkage when forming the inhibitor film will be less, and the packing properties will be better.

[0141] Acetoacetone, as described below, forms a complex with a metal via enolization. [Chem. 59]

[0142] The metal source (B) used in the metal-containing film-forming composition of the present invention is preferably selected from the metals selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi, and the salt of a carboxylic acid with a carbon number of 1 to 30 and a valence of 1 to 4. Specifically, the structure represented by the following formula (B-1) is more preferred. [Chemical 60] In the formula, M is selected from any one of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi, R1 is a monovalent organic group with a carbon number of 1 to 30, and n is an integer from 1 to 4.

[0143] The content of the metal source (B) in the metal-containing film-forming composition is preferably 5-1900 parts by weight relative to 100 parts by weight of resin (A), more preferably 10-900 parts by weight, even more preferably 30-300 parts by weight, and extremely preferably 50-200 parts by weight. A higher content of resin (A) further enhances the thermal fluidity and heat resistance of the metal-containing film-forming composition, resulting in a resist underlayer film with excellent filling and planarization properties. A higher content of the metal source (B) allows for the formation of a resist underlayer film with excellent dry etching resistance. Furthermore, the contribution of the metal-containing film to the improvement of the exposure sensitivity of the resist overlayer film during EUV lithography is greater, which is preferable. These characteristics can be appropriately adjusted according to the requirements of the metal-containing film-forming composition.

[0144] Considering the improvement of exposure sensitivity of the upper layer of EUV photoresist, M in the above formula (B-1) is better if it is Ti, Hf, Sn, or Bi, and Sn is even better.

[0145] <(C) Organic Solvent> As for the organic solvent that can be used in the metal-containing film-forming composition of the present invention, it is not particularly limited as long as it can dissolve or disperse the above-mentioned (A) resin and (B) metal source, as well as (D) crosslinking agent, (E) acid generator, (F) surfactant, and (G) pigment and other additives.

[0146] Specifically, for example, an organic solvent described in paragraphs

[0091] to

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

[0147] The amount of organic solvent incorporated is preferably 200 to 10,000 parts by mass relative to 100 parts by mass of the metal source (B), and more preferably 250 to 5,000 parts by mass.

[0148] <(C') High-boiling-point solvent> In the metal-containing film-forming composition of the present invention, the aforementioned (C) organic solvent may also include (C') high-boiling-point solvent.

[0149] As for (C') high-boiling-point solvents, they may be one or more organic solvents with a boiling point of 180 degrees (°C) or higher.

[0150] For example, with regard to (C) organic solvent, 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 ((C') high boiling point solvent) may also be used.

[0151] Regarding (C') high-boiling-point solvents, there are no particular limitations on hydrocarbons, alcohols, ketones, esters, ethers, chlorinated solvents, etc., as long as they can dissolve or disperse the components of the metal-containing film-forming composition of the present invention. Specific examples include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecaneol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2, 4-Heptanediol, 2-Ethyl-1,3-Hexanediol, Diethylene Glycol, Dipropylene Glycol, Triethylene Glycol, Tripropylene Glycol, Glyceryl, 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 Butylmethyl Ether, Triethylene Glycol Dimethyl Ethers, triethylene glycol monomethyl ether, triethylene glycol n-butyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol n-propyl ether, dipropylene glycol n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol n-propyl ether, tripropylene glycol 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, di... Propylene 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, triethanolamine, etc., may be used alone or in combination.

[0152] (C') A high-boiling-point solvent, and the temperature at which the metal-containing film-forming composition of the present invention is heat-treated, can be appropriately selected from the above, for example. The boiling point of the high-boiling-point solvent is preferably 180°C to 300°C, and more preferably 200°C to 300°C. With such a boiling point, there is no concern that evaporation during baking (heat treatment) will be too rapid, thus suppressing defects caused by drying during film formation. Furthermore, with such a boiling point, the solvent will not remain in the film after baking without evaporation, thus avoiding any adverse effects on film properties such as etching resistance.

[0153] Furthermore, when using a high-boiling-point solvent (C'), the amount of admixture should preferably be 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 an amount of admixture provides sufficient thermal fluidity during baking, does not leave residues in the film, and does not involve deterioration of film properties such as etching resistance, which is therefore preferable.

[0154] <Other Components> The above-mentioned metal-containing film-forming composition may also include, as needed, at least one of (D) crosslinking agent, (E) acid generating agent, (F) surfactant, and (G) pigment.

[0155] Hereinafter, we will describe the components that may be included in the metal-containing film-forming composition of the present invention, other than (A) resin, (B) metal source, and (C) organic solvent.

[0156] [(D) Crosslinking agent] Furthermore, in order to improve the curing properties and further suppress the mixing with the upper film of the inhibitor, the metal-containing film forming composition of the present invention may also contain a (D) crosslinking agent.

[0157] Regarding the crosslinking agent, there are no particular limitations, and crosslinking agents of various known systems can be widely used. For example, 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, acezoline-based crosslinking agents, and epoxy-based crosslinking agents can be cited.

[0158] The crosslinking agent (D) described above can be used alone or in combination of two or more. The amount of crosslinking agent added is preferably 5 to 100 parts, more preferably 10 to 50 parts, relative to 100 parts of resin (A) described above. If the amount added is 5 parts or more, sufficient curing properties will be exhibited, which can suppress mixing with the upper film of the resist. On the other hand, if the amount added is 50 parts or less, there is no concern that the ratio of metal source (B) in the composition will decrease, resulting in a deterioration in dry etching resistance.

[0159] Considering that (B) the metal source is more stable, (D) the crosslinking agent is better if it does not contain hydroxyl groups.

[0160] Melamine-based crosslinking agents include, specifically, hexamethoxymethylated melamine, hexabutoxymethylated melamine, alkoxy and / or hydroxy substituted derivatives of the like, and some of their self-condensates.

[0161] Specifically, examples of glycourea crosslinking agents include tetramethoxymethylated glycourea, tetrabutoxymethylated glycourea, alkoxy and / or hydroxy substituted derivatives of the like, and some of their self-condensates.

[0162] Benzoguanidine crosslinking agents include, specifically, tetramethoxymethylated benzoguanidine, tetrabutoxymethylated benzoguanidine, alkoxy and / or hydroxy substituted derivatives of the like, and some of their self-condensates.

[0163] Urea-based crosslinking agents may specifically include dimethoxyethylene urea with dimethoxymethylation, its alkoxy and / or hydroxyl-substituted derivatives, and some of their self-condensates.

[0164] β-hydroxyalkylamide crosslinking agents, specifically, N,N,N',N'-tetra(2-hydroxyethyl)hexamethylenediamine can be exemplified.

[0165] Isocyanurate crosslinking agents, specifically, include triglycidyl isocyanurate and triallyl isocyanurate.

[0166] Specifically, examples of aziridinium-based crosslinking agents include 4,4'-bis(vinyliminocarbonylamino)diphenylmethane and 2,2-dihydroxymethylbutanol-tris[3-(1-aziridinium)propionate].

[0167] Specifically, examples of acezoline-based crosslinking agents include 2,2'-isopropylidene bis(4-benzyl-2-acezoline), 2,2'-isopropylidene bis(4-phenyl-2-acezoline), 2,2'-methylene bis(4,5-diphenyl-2-acezoline), 2,2'-methylene bis(4-phenyl-2-acezoline), 2,2'-methylene bis(4-tert-butyl-2-acezoline), 2,2'-bis(2-acezoline), 1,3-epylphenyl bis(2-acezoline), 1,4-epylphenyl bis(2-acezoline), and 2-isopropylidene acezoline copolymers.

[0168] Specifically, epoxy crosslinking agents may 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 terephthalol tetraglycidyl ether.

[0169] Examples of epoxy-based and oxetane-based crosslinking agents include, but are not limited to, those listed below. [Chemical 61]

[0170] The above-mentioned compounds are commercially available. Epoxy crosslinking agents and oxetane crosslinking agents can also be obtained by reacting hydroxyl groups with epoxybromopropane, 3-bromomethyloxetane, etc., according to the following formula. In the following formula, R5 is a substituted or unsubstituted monovalent organic group with 1 to 20 carbon atoms (saturated or 2 to 20 carbon atoms), a substituted or unsubstituted aryl group with 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group with 7 to 31 carbon atoms. Alternatively, not all hydroxyl groups may be reacted and left remaining. In this case, it is preferable that the number of epoxides + oxetanes is greater than the number of hydroxyl groups, and more preferably that the number of epoxides + oxetanes is greater than the number of hydroxyl groups * 2.

[0171] The content of these compounds is preferably 5 to 100 parts by mass relative to 100 parts by mass of the metal source (B) mentioned above, and more preferably 10 to 50 parts by mass.

[0172] [Chemical 62]

[0173] The compounds with hydroxyl groups that can be used in the above reaction are specifically listed below, but are not limited to these.

[0174] [Chemistry 63]

[0175] <(E) Acid Generator> In the metal-containing film-forming composition of the present invention, an acid generator may be added to further promote the thermal decomposition reaction of the metal source described in (B) above. The acid generator may be one that generates acid through thermal decomposition or one that generates acid through light exposure; any such generator may be added. Specifically, materials described in paragraphs

[0061] to

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

[0176] 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 mass relative to 100 parts by mass of the metal source (B) above, and more preferably 0.1 to 10 parts.

[0177] <(F) Surfactant> In order to improve the coatability of the metal-containing film-forming composition of the present invention, a surfactant (E) may be added. As for the surfactant, for example, those described in

[0142] to

[0147] of Japanese Patent Application Publication No. 2009-269953 may be used. The amount of surfactant added is preferably 0.01 to 10 parts by weight relative to 100 parts by weight of the metal source (B) mentioned above, and more preferably 0.05 to 5 parts.

[0178] [(H) Pigment] Furthermore, in order to further improve the resolution during patterning of multilayer microfilms, a (H) pigment can be added to the metal-containing film-forming composition of the present invention. Regarding the pigment, there are no particular limitations on compounds that have appropriate absorption for the exposure wavelength, and various known compounds can be widely used. Examples include benzene compounds, naphthalene compounds, anthracene compounds, phenanthrene compounds, pyrene compounds, isocyanuric acid compounds, and triterpenoid compounds. The amount of pigment added is preferably 0.01 to 10 parts by mass relative to 100 parts by mass of the aforementioned (B) metal source, more preferably 0.1 to 5 parts by mass.

[0179] Furthermore, the metal-containing film-forming composition of the present invention may include an alkaline compound to improve storage stability. The alkaline compound acts as an acid quencher, preventing the crosslinking reaction from being induced by trace amounts of acid generated by the acid-generating agent. Specifically, examples of such alkaline compounds can be found in paragraphs (0086) to (0090) of Japanese Patent Application Publication No. 2007-199653.

[0180] Furthermore, in addition to the above, additives for further improving landfill / planarization characteristics may be added to the metal-containing film-forming composition of the present invention. Regarding the additives mentioned above, there are no particular limitations on those that provide landfill / planarization characteristics; for example, liquid additives having polyethylene glycol or polypropylene glycol structures, or thermally degradable polymers with a weight reduction rate of 40% by mass or more from 30°C to 250°C and a weight average molecular weight of 300 to 200,000, are preferable. It is preferable that the thermally degradable polymer contains repeating units of an acetal structure represented by the following general formulas (DP1) and (DP1a).

[0181] [Chemical 64] In the formula, R6 refers to a hydrogen atom or a monovalent organic group with 1 to 30 carbon atoms that may be substituted. Y refers to a divalent organic group with 2 to 30 carbon atoms that may be saturated or unsaturated.

[0182] [Chemical 65] In the formula, R6a is an alkyl group with 1 to 4 carbon atoms. Ya is a saturated or unsaturated divalent hydrocarbon group with 4 to 10 carbon atoms, and may also have an ether bond. n represents the average number of repeating units, which is 3 to 500.

[0183] <Method for forming a metal-containing film> The present invention provides a method for forming a filler film that functions as a resist layer in a multilayer resist film used in lithography, using the above-described metal-containing film forming composition.

[0184] The method for forming a metal-containing film using the metal-containing film forming composition of the present invention involves coating the aforementioned metal-containing film forming composition onto a substrate to be processed using a spin coating method. Good planarity characteristics can be obtained by using spin coating or similar methods. After spin coating, the solvent is evaporated, and baking (heat treatment) is performed to promote the crosslinking reaction in order to prevent mixing with the upper layer of the resist film. Baking is preferably performed in the range of 100°C to 600°C for 10 to 600 seconds, and more preferably in the range of 200°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 of the lithography is preferably below 600°C, and more preferably below 500°C.

[0185] Furthermore, the metal-containing film forming method using the metal-containing film forming composition of the present invention can also coat the metal-containing film forming composition of the present invention onto a substrate by the same spin coating method as described above, and then harden the metal-containing film forming composition by firing it in an ambient gas with an oxygen concentration of 0.1% to 21% by volume, thereby forming a metal-containing film.

[0186] By firing the metal-containing film-forming composition of the present invention in such an oxygen environment, a sufficiently hardened film can be obtained. Air is not a problem as to the ambient gas during baking; however, it is preferable to pre-fill with inert gases such as N2, Ar, or He to reduce oxygen 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). If oxidation of the metal-containing film during baking is prevented, it is preferable to avoid accidents such as increased absorption or decreased etching resistance.

[0187] <Pattern Forming Method> Furthermore, the present invention provides a pattern forming method, which is a pattern forming method using the above-mentioned metal-containing film forming composition with two layers of resist treatment, comprising the following steps: (I-1) coating the metal-containing film forming composition of the present invention on a substrate to be processed, and then forming a metal-containing film by heat treatment; (I-2) forming a resist upper layer film on the metal-containing film using a photoresist material; (I-3) exposing the resist upper layer film to a pattern, and then developing it with a developer to form a pattern on the resist upper layer film; (I-4) using the resist upper layer film with the pattern formed as a mask, transferring the pattern onto the metal-containing film by dry etching; and (I-5) using the metal-containing film with the pattern formed as a mask, processing the substrate to form a pattern on the substrate to be processed.

[0188] The resist upper film of the above two resist treatments exhibits etching resistance to chlorine-based gases. Therefore, in the above two resist treatments, it is better to use chlorine-based etching gases as the main etching gas for dry etching of metal-containing films with the resist upper film as a mask.

[0189] To ensure adhesion to the upper layer of the resistor, an adhesive film can also be formed between the upper layer of the resistor and the metal-containing film of the present invention. The adhesive film can be an organic film or a silicon-containing film containing polysiloxane.

[0190] The patterning method using the resist treatment of the metal-containing film formation composition of the present invention helps to improve the exposure sensitivity of the resist upper film. Therefore, it is preferable to use it as a lower film close to the resist upper film, and even better to use it directly below the resist upper film. When using an adhesive film between the resist upper film and the metal-containing film, the thickness of the adhesive film is preferably 20 nm or less, more preferably 15 nm or less, and even more preferably 10 nm or less. The thinner the adhesive film, the greater the contribution of the metal-containing film to the improvement of the exposure sensitivity of the resist upper film, which is preferable.

[0191] Furthermore, the present invention provides a pattern forming method, which is a pattern forming method using a three-layer resist treatment of such a metal-containing film forming composition, comprising the following steps: (II-1) coating the metal-containing film forming composition of the present invention on a substrate to be processed, and then forming a metal-containing film by heat treatment; (II-2) forming a silicon-containing resist intermediate film on the metal-containing film; (II-3) forming a resist upper film on the silicon-containing resist intermediate film using a photoresist material; (II-4) exposing the resist upper film to a pattern, and then developing it with a developer to form a pattern on the resist upper film; (II-5) using the patterned resist upper film as a mask, and transferring the pattern onto the silicon-containing resist intermediate film by dry etching. (II-6) Using the silicon resist intermediate film with the transferred pattern as a mask, the pattern is transferred onto the metal film by dry etching, and (II-7) Using the metal film with the formed pattern as a mask, the substrate to be processed is processed to form a pattern on the substrate.

[0192] The silicon-containing intermediate film of the above three-layer resist treatment exhibits etching resistance to chlorine-based gases. Therefore, in the above three-layer resist treatment, it is better to use chlorine-based etching gases as the main etching gas for dry etching of metal films with silicon-containing intermediate film as a mask.

[0193] Regarding the silicon-containing intermediate film with the above-mentioned three-layer resist treatment, a polysiloxane-based intermediate film is also preferable. By giving the silicon-containing intermediate film an anti-reflection effect, reflection can be suppressed. Especially for 193nm exposure, if a material containing a large number of aromatic groups and with high etching selectivity with the substrate is used as an organic film, the k-value will become high and the substrate reflection will become high. With the silicon-containing intermediate film, by having absorption that makes it an appropriate k-value, reflection can be suppressed, and the substrate reflection can be set to 0.5% or less. Regarding the silicon-containing intermediate film with anti-reflection effect, for 248nm and 157nm exposure, a polysiloxane with anthracene-based light-absorbing group for suspension and cross-linking due to acid or heat is preferable. For 193nm exposure, a polysiloxane with phenyl or silicon-silicon bond-based light-absorbing group for suspension and cross-linking due to acid or heat is preferable.

[0194] In addition, the present invention provides a pattern forming method, which is a pattern forming method using a four-layer resist treatment of such a metal-containing film forming composition, characterized by having the following steps: forming a metal-containing film on a substrate to be processed using the above-mentioned metal-containing film forming composition; forming a silicon-containing intermediate film on the metal-containing film using a silicon-containing intermediate film material; forming an organic anti-reflective film (BARC) or a sealing film on the silicon-containing intermediate film; and applying a photoresist on the BARC or sealing film. The material forms a resist top layer film. After the resist top layer film is patterned and exposed, it is developed using a developer to form a pattern on the resist top layer film. The patterned resist top layer film is used as a mask, and the pattern is transferred to the BARC or sealing film and the silicon-containing resist intermediate film using dry etching. The patterned silicon-containing resist intermediate film is used as a mask, and the pattern is transferred to the metal-containing film using dry etching. The patterned metal-containing film is used as a mask to process the substrate to form a pattern on the substrate.

[0195] Alternatively, an inorganic hard mask may be formed instead of a silicon resist lower layer film. In this case, at least a metal-containing film may be formed on the workpiece using the metal-containing film forming composition of the present invention. An inorganic hard mask selected from silicon oxide film, silicon nitride film, and silicon oxynitride film may be formed on the metal-containing film. A photoresist composition may be used on the inorganic hard mask to form a resist upper layer film. A circuit pattern may be formed on the resist upper layer film. The patterned resist upper layer film may be used as a mask to etch the inorganic hard mask. The patterned inorganic hard mask may be used as a mask to etch the metal-containing film. The patterned metal-containing film may be used as a mask to etch the workpiece and form a pattern on the workpiece, thereby forming a semiconductor device circuit pattern on the substrate.

[0196] As described above, when forming an inorganic hard mask on a metal-containing film, silicon oxide films, silicon nitride films, and silicon oxynitride films (SiON films) can be formed using methods such as CVD and ALD. For example, regarding the method for forming silicon nitride films, Japanese Patent Application Publication No. 2002-334869 and International Publication No. 2004 / 066377 are disclosed. The thickness of the inorganic hard mask is preferably 5 to 200 nm, and more preferably 10 to 100 nm. Furthermore, for inorganic hard masks, SiON films, which have high anti-reflective properties, are the best choice. The substrate temperature during the formation of SiON films is 300 to 500°C, therefore, the metal-containing film needs to withstand a temperature of 300 to 500°C. The metal-containing film-forming composition used in this invention has high heat resistance and can withstand high temperatures of 300°C to 500°C. Therefore, it can combine an inorganic hard mask formed by CVD or ALD with a metal-containing film formed by spin coating.

[0197] As described above, a photoresist film can also be formed on an inorganic hard mask as a top layer of the resist, or an organic antireflective film (BARC) or a bonding film can be formed on the inorganic hard mask by spin coating. In particular, when using a SiON film as an inorganic hard mask, reflection can be suppressed by using two layers of antireflective films, SiON film and BARC, under immersion exposure at a high NA greater than 1.0. Another advantage of forming BARC is that it reduces the trailing of the photoresist pattern on the SiON film.

[0198] In the above pattern formation method, the resist upper layer film can be either positive or negative, and can be the same as commonly used photoresist composition. Furthermore, the photoresist composition can also contain metal atoms such as Sn, In, Ga, Ge, Al, Ce, La, Cs, Zr, Hf, Ti, Bi, Sb, and Zn. When forming the resist upper layer film using the above photoresist composition, either spin coating or vapor deposition using CVD or ALD methods are acceptable.

[0199] When forming the resist top layer film by spin coating, pre-baking is preferably performed after resist coating at a temperature of 60-180°C for 10-300 seconds. Subsequently, exposure is performed according to conventional methods, followed by post-exposure baking (PEB) and development to obtain the resist pattern. Furthermore, the thickness of the resist top layer film is not particularly limited, but is preferably 10-500 nm, and more preferably 20-400 nm.

[0200] When a resist upper layer film is formed by vapor deposition using CVD or ALD, the aforementioned resist composition is an EUV-sensitive metal oxide film, wherein the aforementioned metal is selected from Sn, Zr, Hf, Ti, Bi, Sb, etc., with Sn having excellent EUV photosensitivity being preferred. The film containing the metal oxide can also be a photosensitive organometallic oxide film such as an organotin oxide (e.g., alkyl halide Sn, alkoxyalkyl Sn, or amide alkyl Sn). Some specific examples of suitable precursors include trimethyltin chloride, dimethyltin dichloride, methyltin trichloride, tris(dimethylamino)methyltin (IV), and (dimethylamino)trimethyltin (IV).

[0201] The metal oxide film, for example, can be deposited using a Lam Vector (registered trademark) device by PECVD or PEALD, wherein in the ALD embodiment, the Sn oxide precursor is separated from the O precursor / plasma. The deposition temperature is preferably in the range of 50°C to 600°C. The deposition pressure is preferably between 100 and 6000 mTorr. The flow rate of the precursor solution containing the metal oxide film (e.g., organotin oxide precursor) can be 0.01 to 10 cm⁻¹, and the gas flow rate (CO₂, CO, Ar, N₂) can be 100 to 10000 sccm. The plasma power, using a high-frequency plasma (e.g., 13.56 MHz, 27.1 MHz, or higher), can be 200 to 1000 W per 300 mm wafer station. The deposition thickness is preferably 100 to 2000 Å.

[0202] In terms of exposure light, it refers to high-energy rays with wavelengths below 300nm, specifically including excimer lasers of 248nm, 193nm, and 157nm, soft X-rays of 3~20nm, electron beams, X-rays, etc.

[0203] Regarding the above-mentioned method for forming the pattern of the upper layer film of the resist, the pattern can be formed by photolithography with a wavelength of 5nm to 300nm, direct drawing by electron beam, nanoimprinting, or a combination thereof. In this invention, EUV light is the best.

[0204] Furthermore, the development method in the aforementioned pattern forming method should preferably be alkaline development or development using organic solvents.

[0205] Then, the obtained resist pattern is used as a mask for etching. The etching of the silicon-containing intermediate film and the inorganic hard mask in the 3-layer resist treatment is performed using a chlorofluorocarbon-based gas and with the upper resist pattern used as a mask. This forms the silicon-containing intermediate film pattern and the inorganic hard mask pattern.

[0206] Then, the obtained silicon resist-containing intermediate film pattern and inorganic hard mask pattern are used as masks to perform etching of the metal-containing film. It is preferable to use an etching gas with chlorine as the main component for etching of the metal-containing film.

[0207] The etching of the following workpieces 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, then etching is performed using a chlorofluorocarbon (CFC) gas. When etching the substrate using a CFC gas, the pattern of the silicon-containing intermediate film in the 3-layer resist treatment will be peeled off simultaneously with the substrate processing.

[0208] 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 workpiece is etched.

[0209] Furthermore, there are no particular limitations regarding the workpiece (the substrate to be processed), and substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al, on which the workpiece layer is formed, can be used. Regarding the workpiece layer, 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, can be used to form thicknesses typically of 50 to 10,000 nm, particularly 100 to 5,000 nm. Moreover, when forming the workpiece layer, the substrate and the workpiece layer can be made of different materials.

[0210] Hereinafter, an example of the pattern formation method of the three-layer resist method of the present invention is shown in Figures 1(A) to (F). In the case of the three-layer resist method, as shown in Figure 1(A), after forming a metal-containing film 3 on the processed layer 2 formed on the processed substrate 1 using the metal-containing film forming composition of the present invention, a silicon-containing resist intermediate film 4 is formed, and a resist upper layer film 5 is formed thereon. Then, as shown in Figure 1(B), the exposure portion 6 of the resist upper layer film 5 is exposed and PEB (post-exposure baking) is performed. Then, as shown in Figure 1(C), development is performed to form the resist upper layer film pattern 5a. Then, as shown in Figure 1(D), the resist upper layer film pattern 5a is used as a mask, and the silicon-containing resist intermediate film 4 is dry-etched using a chlorofluorocarbon gas to form the silicon-containing resist intermediate film pattern 4a. Then, as shown in Figure 1(E), after removing the resist upper film pattern 5a, the silicon resist-containing intermediate film pattern 4a is used as a mask, and the metal-containing film 3 is dry-etched using chlorine gas to form the metal-containing film pattern 3a. Furthermore, as shown in Figure 1(F), after removing the silicon resist-containing intermediate film pattern 4a, the metal-containing film pattern 3a is used as a mask, and the layer 2 to be processed is etched to form pattern 2a.

[0211] When forming an inorganic hard mask, the silicon resist-containing intermediate film 4 can be replaced with an inorganic hard mask. When forming a BARC, a BARC can be formed between the silicon resist-containing intermediate film 4 and the resist upper film 5. The etching of the BARC can be carried out continuously before the etching of the silicon resist-containing intermediate film 4, or the etching of the silicon resist-containing intermediate film 4 can be carried out by changing the etching apparatus after the etching of only the BARC is carried out.

[0212] The present invention also provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed, comprising the following steps: (III-1) coating the metal-containing film forming composition of the present invention on the substrate to be processed, and then forming a metal-containing film by heat treatment; (III-2) forming an inorganic hard mask intermediate film selected from silicon oxide film, silicon nitride film, and silicon oxynitride film on the metal-containing film; (III-3) forming an organic film on the inorganic hard mask intermediate film; (III-4) forming a resist upper layer film on the organic film using a photoresist material; (III-5) exposing the resist upper layer film to a pattern, and then developing it with a developer to form a pattern on the resist upper layer film; (III-6) using the patterned resist upper layer film as a mask, and transferring the pattern to the organic film and the inorganic hard mask intermediate film by dry etching. (III-7) Using the inorganic hard mask intermediate film with the transferred pattern as a mask, the pattern is transferred onto the metal-containing film by dry etching, and (III-8) Using the metal-containing film with the formed pattern as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed.

[0213] Furthermore, the present invention provides a pattern forming method, which is a pattern forming method using a four-layer resist treatment of a metal-containing film forming composition as described above, comprising the following steps: (IV-1) coating the metal-containing film forming composition of the present invention onto a substrate to be processed, and then forming a metal-containing film by heat treatment; (IV-2) forming an organic intermediate film on the metal-containing film; (IV-3) forming a silicon resist-containing intermediate film, or a combination of an inorganic hard mask intermediate film and an organic thin film selected from silicon oxide film, silicon nitride film, and silicon oxynitride film, on the organic intermediate film; (IV-4) forming a resist upper layer film using a photoresist material on the silicon resist-containing intermediate film or the organic thin film; (IV-5) after pattern exposure of the resist upper layer film, developing it with a developer to form a pattern on the resist upper layer film. (IV-6) Using the patterned resist top film as a mask, the pattern is transferred to the silicon resist intermediate film or the organic film and the inorganic hard mask intermediate film by dry etching. (IV-7) Using the patterned silicon resist intermediate film or the inorganic hard mask intermediate film as a mask, the pattern is transferred to the organic intermediate film by dry etching. (IV-8) Using the organic intermediate film as a mask, the pattern is transferred to the metal film by dry etching. (IV-9) Using the patterned metal film as a mask, the substrate is processed to form a pattern on the substrate.

[0214] As an example of a pattern forming method using a four-layer resist treatment with such a metal-containing film forming composition, the present invention provides a pattern forming method characterized by comprising the following steps: forming a metal-containing film on a substrate using the aforementioned metal-containing film forming composition; forming an organic intermediate film on the metal-containing film using an organic resist intermediate film material; forming a silicon-containing resist intermediate film on the organic intermediate film using a silicon-containing resist intermediate film material; forming an organic anti-reflective film (BARC) or an adhesive film on the silicon-containing resist intermediate film as needed; and forming an organic anti-reflective film (BARC) or an adhesive film on the silicon-containing film or the BARC. A photoresist material is used to form a top resist film on the ARC. After the top resist film is patterned and exposed, it is developed using a developer to form a pattern on the top resist film. The patterned top resist film is used as a mask, and the pattern is transferred to the BARC or sealing film and the silicon-containing intermediate film using dry etching. The patterned silicon-containing intermediate film is used as a mask, and the pattern is transferred to the organic intermediate film using dry etching. The organic intermediate film is used as a mask to transfer the pattern to the metal-containing film. The patterned metal-containing film is used as a mask to process the substrate to form a pattern on the substrate.

[0215] Regarding organic inhibitor intermediate film materials that can be used in the above-mentioned organic intermediate films, in addition to the 4,4'-(9-pyroxene)bisphenol phenolic varnish resin (molecular weight 11,000) disclosed in Japanese Patent Application Publication No. 2005-128509, which is known as a lower film for use in the 3-layer inhibitor method or the 2-layer inhibitor method using a silicone inhibitor composition, many other resins such as phenolic varnish resins can be used, and are known as inhibitor lower film materials for the 2-layer inhibitor method and the 3-layer inhibitor method. Furthermore, when it is desired to have higher heat resistance than ordinary phenolic varnishes, a polycyclic skeleton such as 6,6'-(9-pyroxene)-bis(2-naphthol)phenolic varnish resin can be added, and polyimide resins can also be selected (for example, Japanese Patent Application Publication No. 2004-153125).

[0216] The above-mentioned organic intermediate film can be formed on the substrate being processed using a composition solution, similar to a photoresist composition, by spin coating or the like. After forming the organic intermediate film by spin coating or the like, it is ideal to bake it to allow the organic solvent to evaporate. A baking temperature in the range of 80 to 400°C and a baking time in the range of 10 to 300 seconds are preferred.

[0217] Alternatively, an organic hard mask formed by CVD or ALD can be used to replace the above-mentioned organic resist intermediate film material.

[0218] The organic intermediate film treated with the above-mentioned multilayer resist exhibits etching resistance to chlorine-based gases. Therefore, in the above-mentioned multilayer resist treatment, it is better to use an etching gas whose main component is chlorine-based gas for dry etching of the metal-containing film using the organic intermediate film as a mask.

[0219] The present invention also provides a pattern forming method, which is a method for forming a tone-reversed pattern on a substrate to be processed, comprising the following steps: (V-1) forming a lower resist film on the substrate to be processed; (V-2) forming a resist intermediate film or a combination of an inorganic hard mask intermediate film and an organic thin film selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film on the lower resist film; (V-3) forming a resist upper film on the resist intermediate film or the combination of inorganic hard mask intermediate film and organic thin film using a photoresist material; (V-4) after exposing the resist upper film to a pattern, developing it with a developer to form a pattern on the resist upper film; (V-5) using the resist upper film with the pattern formed as a mask, transferring the pattern onto the resist intermediate film, or the organic thin film and the inorganic hard mask intermediate film by dry etching. (V-6) Using the resist interlayer film or inorganic hard mask interlayer film with the transferred pattern as a mask, the pattern is transferred onto the resist underlayer film by dry etching. (V-7) After coating the resist underlayer film with the pattern formed with the metal-containing film composition of the present invention, the metal-containing film is coated by heat treatment, and the spaces between the patterns of the resist underlayer film are filled with the metal-containing film. (V-8) The metal-containing film covering the resist underlayer film with the pattern formed is chemically stripped or dry-etched to expose the top surface of the resist underlayer film with the pattern formed. (V-9) The resist interlayer film or hard mask interlayer film remaining on the top surface of the resist underlayer film is removed by dry etching. (V-10) The resist underlayer film with the pattern formed on the exposed surface is removed by dry etching to form a reversed pattern of the original pattern composed of the metal-containing film. (V-11) The metal-containing film with the inverted pattern is used as a mask to process the substrate to form an inverted pattern on the substrate.

[0220] An example of the tone reversal pattern forming method of the present invention will be described with reference to FIG2. Steps (V-1) to (V-6) can be performed in the same manner as FIG1(A) to (E) except that the metal-containing film 3 is replaced with a resist lower film 7 composed of a coating-type organic lower film material to form a resist lower film pattern 7a. (FIG. 2(G) to (K)) In step (V-7), after coating the resist lower film 7 with the metal-containing film forming composition of the present invention, a metal-containing film 8 is coated by heat treatment, and the resist lower film patterns 7a are filled with the metal-containing film 8 (FIG. 2(L)). In step (V-8), the metal-containing film 8 covering the resist lower film 7 with the pattern is chemically stripped or dry etched back to expose the top surface of the resist lower film 7 with the pattern (FIG. 2(M)). In step (V-9), the residual resist intermediate film or the aforementioned hard mask intermediate film on the top surface of the resist lower layer film 7 is removed by dry etching (Fig. 2(N)). In step (V-10), the resist lower layer film 7 with the exposed surface pattern is removed by dry etching to form a metal-containing film pattern 8a that reverses the resist lower layer film pattern composed of the metal-containing film 8 (Fig. 2(O)). In step (V-11), the metal-containing film 8 with the reversed pattern is used as a mask to process the processed substrate 2 to form pattern 2a (reverse pattern) on the processed substrate.

[0221] Furthermore, in the pattern forming method of the present invention, it is preferable to use EUV light to expose the aforementioned pattern in steps (I-3), (II-4), (III-5), (IV-5), and (V-4). [Example]

[0222] Hereinafter, synthetic examples, embodiments and comparative examples will be given to illustrate the present invention in more detail, but the present invention is not limited thereto.

[0223] [Metal-containing film forming compounds (M-1)~(M-17)] The metal-containing film forming compounds use the following metal compounds (metal salts). (M-1): Titanium 2-ethylhexanoate (IV) (M-2): Tris(2,2,6,6-tetramethyl-3,5-heptadecanoate)chromium (III) (M-3): Tris(2,2,6,6-tetramethyl-3,5-heptadecanoate)manganese (III) (M-4): Tris(2,2,6,6-tetramethyl-3,5-heptadecanoate)iron (III) (M-5): Cobalt 2-ethylhexanoate (II) (M-6): Bis(hexafluoroacetylene)nickel (II) (M-7): Copper 2-ethylhexanoate (I) (M-8): Zinc 4-vinylbenzoate (II) (M-9): Zirconium tetrakis(2,2,6,6-tetramethyl-3,5-heptadecanoate)zirconium (IV) (M-10): Molybdenum 2-ethylhexanoate (IV) (M-11): Indium ethylbutyrate (III) (M-12): Tin acetate (II) (M-13): Tin 2-ethylhexanoate (II) (M-14): Tin acetone (II) (M-15): Tin 4-fluorophenylacetate (II) (M-16): Hafnium(IV) carboxyethyl acrylate (M-17): Bismuth(III) 2-ethylhexanoate

[0224] [Crosslinking agents (XL-1)~(XL-2)] Crosslinking agents (XL-1)~(XL-2) used in metal-containing film-forming compositions are shown below. [Chemical 66]

[0225] [Acid Generator (D-1)] The acid generator (D-1) using a metal-containing film-forming composition is shown below. [Chemical 67]

[0226] [Flowability Accelerator (BPA-1)~(BPA-7)] (Synthesis of Flowability Accelerator) The flowability accelerator (resin) is synthesized using the organic raw material group g: (G1)~(G7) and the modifying agent H: (H1)~(H5) shown below.

[0227] Organic-based raw material groups g: (G1)~(G7) are shown below. [Chem. 68]

[0228] Modifying groups H: (H1)~(H5) are shown below. [Chemistry 69]

[0229] [Synthesis Example 1] Synthesis of Flow Enhancer (BPA-1): Under nitrogen atmosphere, 20.0 g of N-methylpyrrolidone was added to 20.0 g of compound (G1) from the raw material group, 16.4 g of modifier (H1), and 23.3 g of potassium carbonate, and the reaction was carried out at an internal temperature of 140°C for 24 hours. After cooling to room temperature, 300 ml of methyl isobutyl ketone and 300 ml of pure water were added to the reaction solution to homogenize it, and the separated aqueous layer was removed. The organic layer was then washed twice with 100 ml of 3% nitric acid aqueous solution and five times with 100 ml of pure water, and then dried under reduced pressure. 100 g of THF was added to the residue to form a homogeneous solution, and then crystallization was performed with 350 g of methanol. The precipitated crystals were filtered to separate them, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70°C to obtain compound (BPA-1) for flow enhancement. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the results are as follows. (BPA-1): Mw = 580, Mw / Mn = 1.03 [Chem. 70]

[0230] [Synthesis Example 2] Synthesis of Flowability Improver (BPA-2): Under nitrogen atmosphere, 45.5g of compound (G2) from the raw material group, 9.8g of potassium carbonate, and 150g of DMF were added, and the mixture was uniformly dispersed at an internal temperature of 50°C. 17.6g of a modifying agent (H2) was slowly added, and the mixture was reacted at an internal temperature of 50°C for 24 hours. 300ml of methyl isobutyl ketone and 300g of pure water were added to the reaction mixture to dissolve the precipitated salt, and the separated aqueous layer was removed. The organic layer was then washed six times with 100g of 3% nitric acid aqueous solution and 100g of pure water, and then dried under reduced pressure to obtain compound (BPA-2) for flowability improvement. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the results are as follows: (BPA-2): Mw=965, Mw / Mn=1.08 [Chem. 71]

[0231] [Synthesis Example 3] Synthesis of flowability enhancer (BPA-3): Under nitrogen atmosphere, 47.2 g of compound (G3), 11.7 g of potassium carbonate, and 150 g of DMF were added, and the mixture was heated to 50°C to form a uniform dispersion. 17.2 g of modifier (H3) was slowly added, and the mixture was reacted at 50°C for 24 hours. 300 ml of methyl isobutyl ketone and 300 g of pure water were added to the reaction solution to dissolve the precipitated salt, and the separated aqueous layer was removed. The organic layer was then washed 6 times with 100 g of 3% nitric acid aqueous solution and 100 g of pure water, and then dried under reduced pressure to obtain the flowability enhancer polymer (BPA-3). The weight average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the results are as follows: (BPA-3): Mw = 740, Mw / Mn = 1.03 [Chem. 72]

[0232] [Synthesis Example 4] Synthesis of Flow Enhancer (BPA-4): Under nitrogen atmosphere, 100g of N-methylpyrrolidone was added to 30.00g of compound (G4) from the raw material group. After forming a homogeneous solution at an internal temperature of 40°C under nitrogen atmosphere, 13.7g of modifying agent (H4) was added, and the reaction was carried out at an internal temperature of 40°C for 3 hours to obtain a acetic acid solution. 200g of o-xylene was added to the obtained acetic acid solution, and the reaction was carried out at an internal temperature of 150°C for 9 hours to remove the generated low-boiling substances and water from the system to carry out dehydration acetylation. After the reaction was completed, the solution was cooled to room temperature and crystallized in 1000g of methanol. The precipitated crystals were separated by filtration, washed twice with 500g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain compound (BPA-4) for flow enhancement. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the results are as follows. (BPA-4): Mw = 930, Mw / Mn = 1.01 [Chem. 73]

[0233] [Synthesis Example 5] Synthesis of Flowability Improver (BPA-5): Under nitrogen atmosphere, 44.7 g of compound (G5) from the raw material group, 16.5 g of potassium carbonate, and 150 g of DMF were added, and the mixture was heated to 50°C to form a uniform dispersion. 23.5 g of a modifier (H2) was slowly added, and the mixture was reacted at 50°C for 24 hours. 300 ml of methyl isobutyl ketone and 300 g of pure water were added to the reaction mixture to dissolve the precipitated salt, and the separated aqueous layer was removed. The organic layer was then washed six times with 100 g of 3% nitric acid aqueous solution and 100 g of pure water, and then dried under reduced pressure to obtain the flowability improver polymer (BPA-5). The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the results are as follows: (BPA-5): Mw = 2700, Mw / Mn = 3.20 [Chem. 74]

[0234] [Synthesis Example 6] Synthesis of Flowability Improver (BPA-6): Under nitrogen atmosphere, 20.0 g of compound (G6) from the raw material group, 34.5 g of potassium carbonate, and 100 g of DMF were added, and the mixture was heated to 50°C to form a uniform dispersion. 23.8 g of modifying agent (H2) was slowly added, and the mixture was reacted at 50°C for 24 hours. 300 ml of methyl isobutyl ketone and 300 g of pure water were added to the reaction solution to dissolve the precipitated salt, and the separated aqueous layer was removed. The organic layer was then washed six times with 100 g of 3% nitric acid aqueous solution and 100 g of pure water, and then dried under reduced pressure to obtain resin (BPA-6). The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the results are as follows: (BPA-6): Mw = 9,400, Mw / Mn = 3.59 [Chem. 75]

[0235] [Synthesis Example 7] Synthesis of Flow Improver (BPA-7) 80.0 g of epoxy compound (G7), 51.0 g of modifying agent (H5), and 600 g of 2-methoxy-1-propanol were mixed under nitrogen atmosphere at an internal temperature of 100°C to form a homogeneous solution. Then, 5.7 g of benzyltriethylammonium chloride was added and the mixture was stirred at an internal temperature of 120°C for 12 hours. After cooling to room temperature, 1,500 g of methyl isobutyl ketone was added, and the organic layer was washed five times with 300 g of pure water. The organic layer was dried under reduced pressure to obtain the flow improver compound (BPA-7). The weight average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the results are as follows: (BPA-7): Mw = 900, Mw / Mn = 1.04 [Chem. 76]

[0236] The structures, weight-average molecular weights (Mw), and dispersities (Mw / Mn) of the compounds and polymers used in the obtained flowability improvers are shown in Tables 1 and 2. For the comparative polymer (R-1), raw material group G (G5) used as the raw material in the synthesis example was used.

[0237] [Table 1]

[0238] [Table 2]

[0239] [Comparative Example: Synthesis of a Metal-Containing Film-Forming Compound (RM-1)] 8.0 g of butyltin trichloride was stirred at room temperature, and 10 g of acrylic acid was added dropwise. After the addition, the temperature was raised to 80°C, and the mixture was stirred for 7 hours. After the reaction was completed, the acrylic acid was removed by vacuum to obtain (RM-1). [Chemical 77]

[0240] [Metal-containing film forming composition UDL-1] Resin BPA-1 and metal salt (M-13) were dissolved in a mixed solvent containing 0.5% by mass surfactant FC-4430 (manufactured by Sumitomo 3M) in propylene glycol monomethyl ether acetate (PGMEA) at the proportions shown in Table 3, and filtered through a 0.02 μm membrane filter to prepare a metal-containing film forming composition (UDL-1).

[0241] [Preparation of Metal-Containing Film-Forming Compositions (UDL-2~27) and Comparative Examples of Metal-Containing Film-Forming Compositions (Comparative Examples UDL-1~5)] The types and contents of each component are set as shown in Table 3. Except for the above, each drug solution was prepared in the same manner as UDL-1. In Table 3, "-" indicates that the component was not used. The high-boiling-point solvent (F-1) used was ethylene glycol dibenzyl ether: boiling point 364°C. The metal nanoparticles (NP-1) used were ZrO2 nanoparticles (5nm core, 915505, Sigma-Aldrich Corp.).

[0242] [Table 3] Metal-containing film Forming components resin Metal-containing film Compounds for formation additive solvent (parts by weight) (parts by weight) (parts by weight) (parts by weight) UDL-1 BPA-1(5) M-13(5) - PGMEA(100) UDL-2 BPA-2(5) M-13(5) - PGMEA(100) UDL-3 BPA-3(5) M-13(5) - PGMEA(100) UDL-4 BPA-4(5) M-13(5) - PGMEA(100) UDL-5 BPA-5(5) M-13(5) - PGMEA(100) UDL-6 BPA-6(5) M-13(5) - PGMEA(100) UDL-7 BPA-7(5) M-13(5) - PGMEA(100) UDL-8 BPA-2(5) M-13(5) F-1(1) PGMEA(100) UDL-9 BPA-2(5) M-13(5) XL-1(1) PGMEA(100) UDL-10 BPA-2(5) M-13(5) XL-2(1) D-1(0.5) PGMEA(100) UDL-11 BPA-1(5) M-1(5) - PGMEA(100) UDL-12 BPA-2(5) M-2(5) - PGMEA(100) UDL-13 BPA-3(5) M-3(5) - PGMEA(100) UDL-14 BPA-4(5) M-4(5) - PGMEA(100) UDL-15 BPA-5(5) M-5(5) - PGMEA(100) UDL-16 BPA-6(5) M-6(5) - PGMEA(100) UDL-17 BPA-7(5) M-7(5) - PGMEA(100) UDL-18 BPA-1(5) M-8(5) - PGMEA(100) UDL-19 BPA-2(5) M-9(5) - PGMEA(100) UDL-20 BPA-3(5) M-10(5) - PGMEA(100) UDL-21 BPA-4(5) M-11(5) - PGMEA(100) UDL-22 BPA-5(5) M-12(5) - PGMEA(100) UDL-23 BPA-6(5) M-13(5) - PGMEA(100) UDL-24 BPA-7(5) M-14(5) - PGMEA(100) UDL-25 BPA-1(5) M-15(5) - PGMEA(100) UDL-26 BPA-2(5) M-16(5) - PGMEA(100) UDL-27 BPA-3(5) M-17(5) - PGMEA(100) Comparative example UDL-1 BPA-3(5) - - PGMEA(100) Comparative example UDL-2 - M-13(10) - PGMEA(100) Comparative example UDL-3 BPA-3(5) - NP-1(5) PGMEA(100) Comparative example UDL-4 BPA-3(5) RM-1(5) - PGMEA(100) Comparative example UDL-5 R-1(5) M-13(5) - PGMEA(100)

[0243] Among the metal-containing film-forming compositions prepared above, comparative example UDL-5, which used a resin containing phenolic hydroxyl groups, showed the formation of precipitates, and therefore subsequent evaluations were discontinued. On the other hand, no precipitates were observed in the metal-containing film-forming compositions UDL-1 to 27 of the present invention. It is presumed that this is because the resin used in the flowability enhancer does not contain phenolic hydroxyl groups.

[0244] [Examples 1-1~1-27, Comparative Examples 1-1~1-4: Etching Resistance] Metal-containing film forming compositions (UDL-1~27 and Comparative Examples UDL-1~4) were coated on a silicon substrate. A metal-containing film with a thickness of 80 nm was formed by heating at 350°C for 60 seconds using a heating plate, and the film thickness A was measured. Then, etching was performed for 30 seconds using CF4 gas under the following conditions using a TE-8500 dry etching apparatus manufactured by Tokyo Powertech Co., Ltd., and the film thickness B was measured. The film thickness etched for 30 seconds (film thickness B - film thickness A) was calculated as the etching resistance.

[0245] In the etching using CF4 gas, cases where the film thickness difference between B and A is less than 30 nm are rated as "A" (very good), cases where the difference is more than 30 nm but less than 50 nm are rated as "B" (good), and cases where the difference is more than 50 nm are rated as "C" (poor). The results are shown in Table 4.

[0246] Dry etching conditions using CF4 gas: Chamber pressure: 100mT; RF power (upper part): 500W; RF power (lower part): 400W; CF4 gas flow rate: 300sccm; Time: 30sec

[0247] [Table 4] Example Metal-containing film Forming components Etching resistance CF4 Example 1-1 UDL-1 A Examples 1-2 UDL-2 A Examples 1-3 UDL-3 A Examples 1-4 UDL-4 A Examples 1-5 UDL-5 A Examples 1-6 UDL-6 B Examples 1-7 UDL-7 B Examples 1-8 UDL-8 A Examples 1-9 UDL-9 A Examples 1-10 UDL-10 A Examples 1-11 UDL-11 A Examples 1-12 UDL-12 A Examples 1-13 UDL-13 A Examples 1-14 UDL-14 A Examples 1-15 UDL-15 A Examples 1-16 UDL-16 B Examples 1-17 UDL-17 B Examples 1-18 UDL-18 A Examples 1-19 UDL-19 A Examples 1-20 UDL-20 A Examples 1-21 UDL-21 A Examples 1-22 UDL-22 A Examples 1-23 UDL-23 B Examples 1-24 UDL-24 B Examples 1-25 UDL-25 A Examples 1-26 UDL-26 A Examples 1-27 UDL-27 A Comparative Example 1-1 Comparative example UDL-1 C Comparative Examples 1-2 Comparative example UDL-2 A Comparative Examples 1-3 Comparative example UDL-3 A Comparative Examples 1-4 Comparative example UDL-4 B

[0248] As shown in Table 4, it can be seen that Examples 1-1 to 1-27 using the metal-containing film-forming composition of the present invention exhibit good etch resistance to CF4 gas. In particular, the metal-containing film-forming composition using a flow promoter (BPA-1 to 5) containing a caloric structure exhibits excellent dry etching resistance.

[0249] On the other hand, the dry etching resistance of Comparative Example UDL-1, which does not contain the (B) metal source, is insufficient. Furthermore, for Comparative Example UDL-4, which uses an organotin compound (RM-1) that is not a complex with carboxylates or β-diketones as the metal source, the dry etching resistance is improved compared to Comparative Example UDL-1, which only contains a flow promoter. However, it is presumed that this is because the organotin compound (RM-1) has insufficient heat resistance and hardening properties, or because the proportion of metal oxides contained in the resist underlayer film is low, and the dry etching resistance is not sufficiently improved.

[0250] [Examples 2-1~2-27, Comparative Examples 2-1~2-4: Evaluation of Landfill Characteristics / Planarization Characteristics] The above-mentioned metal-containing film forming compositions (UDL-1~27, Comparative Examples UDL-1~4) were respectively coated on a SiO2 wafer substrate with a dense line and spacing pattern (line width 60nm, line depth 100nm, distance between the centers of two adjacent lines 120nm). A metal-containing film with a film thickness of 80nm was formed by heating with a heating plate at the temperature shown in Table 5 for 60 seconds. The substrate used is the substrate 9 (SiO2 wafer substrate) with a dense line and spacing pattern shown in Figures 3(Q) (top view) and (R) (cross view).

[0251] The cross-sectional shape of each obtained wafer substrate was observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd. to confirm whether it could be embedded into the substrate with a high-low difference. The results are shown in Table 5.

[0252] When using a metal-containing film-forming composition with poor filling properties, it was not possible to successfully fill the substrate with unevenness in this evaluation. When using a metal-containing film-forming composition with good filling properties, in this evaluation, as shown in FIG3(S), the metal-containing resist lower layer film 10 can fill the gaps between the lines of the substrate 9 with a dense line and spacing pattern without gaps. "Good" means that it can fill without large gaps, and "poor" means that it cannot be filled.

[0253] Furthermore, as shown in Figure 4, the cross-sectional shapes of each wafer substrate 11 obtained in the above landfill evaluation were observed using a scanning electron microscope (SEM). The height difference (Delta 12 in Figure 4(U)) of the filler film (metal resist lower layer film 12) in the densely lined areas and the non-lined areas was observed using a Hitachi electron microscope (S-4700). The results are shown in Table 5. In this evaluation, the smaller the height difference, the better the planarization characteristics.

[0254] [Table 5] Example Metal-containing film Forming components landfill Flatness Baking temperature 60LS nm ℃ Example 2-1 UDL-1 good 30 350 Example 2-2 UDL-2 good 28 350 Example 2-3 UDL-3 good 30 350 Examples 2-4 UDL-4 good 32 350 Examples 2-5 UDL-5 good 33 350 Examples 2-6 UDL-6 good 29 350 Examples 2-7 UDL-7 good 28 350 Examples 2-8 UDL-8 good 26 350 Examples 2-9 UDL-9 good 28 350 Example 2-10 UDL-10 good 29 350 Example 2-11 UDL-11 good 31 350 Example 2-12 UDL-12 good 29 350 Example 2-13 UDL-13 good 30 350 Example 2-14 UDL-14 good 32 350 Example 2-15 UDL-15 good 33 350 Example 2-16 UDL-16 good 30 350 Example 2-17 UDL-17 good 29 350 Example 2-18 UDL-18 good 30 350 Example 2-19 UDL-19 good 29 350 Example 2-20 UDL-20 good 30 350 Example 2-21 UDL-21 good 31 350 Example 2-22 UDL-22 good 33 350 Example 2-23 UDL-23 good 30 350 Example 2-24 UDL-24 good 28 350 Example 2-25 UDL-25 good 32 350 Example 2-26 UDL-26 good 30 350 Example 2-27 UDL-27 good 30 350 Comparative Example 2-1 Comparative example UDL-1 good 29 350 Comparative Example 2-2 Comparative example UDL-2 bad 33 350 Comparative Examples 2-3 Comparative example UDL-3 good 29 350 Comparative Examples 2-4 Comparative example UDL-4 bad 34 350

[0255] As shown in Table 5, it can be confirmed that when the metal-containing film-forming composition of the present invention is baked at 350°C, the dense line and spacing patterns can be filled without voids, exhibiting good filling characteristics. Considering the flow promoter contained in the metal-containing film-forming composition, the examples using propargyl resins (BPA-2, 4-7) exhibit excellent planarization characteristics. In particular, the examples using the densely structured BPA-6, 7 resins exhibit excellent planarization characteristics. Furthermore, examples using a high-boiling-point solvent (F-1) in Examples 2-8 show even better planarization results.

[0256] On the other hand, in Comparative Example 2-2, which uses Comparative Example UDL-2 without a flow promoter (resin), gaps were observed at the bottom of the pattern. It is speculated that these gaps are caused by the volume shrinkage of the metal compound during baking.

[0257] Furthermore, in Comparative Examples 2-4, using Comparative Example UDL-4, which contains a comparative example compound (RM-1) containing a monomolecular tin compound, gaps were observed at the bottom of the pattern. It is presumed that this is due to insufficient heat resistance and hardening properties of compound (RM-1).

[0258] [Examples 3-1~3-10, Comparative Examples 3-1~3-4: Pattern Formation Method] The above-mentioned metal-containing film formation composition (UDL-1~10, and Comparative Examples UDL-1~4) was applied to a Si substrate on which a 100 nm SiO2 film was formed. Spin coating was performed, and the substrate was baked at 350°C for 60 seconds to form a lower resist layer film with a thickness of 80 nm. A silicon-atom-containing resist intermediate layer material (SOG-1) was coated onto this layer and baked at 220°C for 60 seconds to form a resist intermediate layer film with a thickness of 30 nm. An ArF monolayer resist of the upper resist layer material was coated onto this layer and baked at 105°C for 60 seconds to form a photoresist film with a thickness of 100 nm. A wetting protective film material (TC-1) was coated onto the photoresist film and baked at 90°C for 60 seconds to form a protective film with a thickness of 50 nm.

[0259] Regarding the silicon-containing inhibitor interlayer material (SOG-1), the polymer represented by ArF silicon-containing interlayer polymer (SiP1) and the crosslinking catalyst (CAT1) are dissolved in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M) in the proportions shown in Table 6, and filtered through a fluoropolymer filter with a pore size of 0.1 μm to prepare the silicon-containing inhibitor interlayer material (SOG-1).

[0260] [Table 6] polymer Thermal crosslinking catalyst organic solvents (parts by weight) (parts by weight) (parts by weight) SOG-1 SiP1 (100) CAT1 (1) Propylene glycol monoethyl ether (4000)

[0261] Regarding the upper layer film material of the inhibitor (single-layer inhibitor for ArF), it is prepared by dissolving the polymer (RP1), acid generator (PAG1), and basic compound (Amine1) in a solvent containing 0.1% by mass of surfactant FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 7, and filtering it through a 0.1 μm fluororesin filter.

[0262] [Table 7] polymer (parts by weight) Acid generating agent (parts by weight) alkaline compounds (parts by weight) solvent (parts by weight) ArF uses Single-layer inhibitor RP1 (100) PAG1 (6.6) Amine1 (0.8) PGMEA (2,500)

[0263] The polymer (RP1), acid generator (PAG1), and basic compound (Amine1) used in the upper layer film material of the inhibitor (a single-layer inhibitor for ArF) are shown below. [Chemistry 78]

[0264] As for the impregnated protective film material (TC-1), it is prepared by dissolving the protective film polymer (PP1) in an organic solvent at the proportions in Table 8 and filtering it through a 0.1 μm fluororesin filter.

[0265] [Table 8] Protective film polymer (parts by weight) organic solvents (parts by weight) TC-1 PP1 (100) Diisopentyl ether (2,700) 2-Methyl-1-butanol (270)

[0266] The protective film polymer (PP1) used in the impregnation protective film material (TC-1) is shown below. [Chemical 79]

[0267] Then, the exposure was performed using an ArF immersion exposure apparatus (Nikon Corporation; NSR-S610C, NA1.30, σ0.98 / 0.78, 35-degree dipole s-polarized illumination, 6% half-step phase shift mask), and baked at 100°C (PEB) for 60 seconds. Then, it was developed using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to obtain a 50 nm 1:1 positive line and spacing pattern (resistor upper film pattern).

[0268] Then, using a ULVAC CE-300I etching apparatus, the upper resist film pattern was used as a mask to etch the silicon-containing intermediate resist film to form a resist intermediate film pattern. The obtained resist intermediate film pattern was used as a mask to etch the lower resist film to form a pattern. The obtained lower resist film pattern was used as a mask to perform the etching process on the SiO2 film. The etching conditions are as follows.

[0269] The cross-section of the pattern was observed using an S-4700 (Hitachi, Ltd. electron microscope). Furthermore, the length of the processed line was measured using a Hitachi Advanced Semiconductor Magnetic Analyzer (S9200), and the line length (LWR) was observed. The results are shown in Table 9.

[0270] Transfer conditions of the resist upper film pattern to the silicon-containing resist intermediate film. Dry etching conditions using CF4 gas: Pressure: 1 Pa; Antenna RF power: 100 W; Bias RF power: 15 W; CF4 gas flow rate: 15 sccm; Time: 20 sec

[0271] Transfer conditions of the silicon resist-containing intermediate film to the resist-containing lower film. Dry etching conditions using Cl2 gas: Pressure: 1 Pa; Antenna RF power: 320 W; Bias RF power: 30 W; Cl2 gas flow rate: 25 sccm; Time: 60 sec

[0272] Transfer conditions of the resist underlayer pattern to the SiO2 film. Dry etching conditions using CF4 gas: Pressure: 1 Pa; Antenna RF power: 100 W; Bias RF power: 15 W; CF4 gas flow rate: 15 sccm; Time: 60 sec

[0273] [Table 9] Example Metal-containing film Forming components After substrate processing Pattern Shape cross-sectional shape LWR Example 3-1 UDL-1 Vertical shape 2.4 Example 3-2 UDL-2 Vertical shape 2.3 Example 3-3 UDL-3 Vertical shape 2.3 Examples 3-4 UDL-4 Vertical shape 2.4 Examples 3-5 UDL-5 Vertical shape 2.3 Examples 3-6 UDL-6 Vertical shape 2.6 Examples 3-7 UDL-7 Vertical shape 2.5 Examples 3-8 UDL-8 Vertical shape 2.3 Examples 3-9 UDL-9 Vertical shape 2.3 Examples 3-10 UDL-10 Vertical shape 2.4 Comparative Example 3-1 Comparative example UDL-1 Push-out shape 3.6 Comparative Example 3-2 Comparative example UDL-2 Vertical shape 2.4 Comparative Example 3-3 Comparative example UDL-3 Vertical shape 3.3 Comparative Examples 3-4 Comparative example UDL-4 Push-out shape 3.4

[0274] As shown in Table 9, the metal-containing film-forming compositions (UDL-1 to 10) of the present invention were confirmed to transfer the resist upper film pattern well to the substrate, making them suitable for use in micro-processing by multilayer resist methods. In particular, the embodiments using metal-containing film-forming compositions (BPA-1 to 5) containing a flow promoter with a caloric structure, which exhibited excellent dry etching resistance in the above evaluation, demonstrated excellent LWR.

[0275] In contrast, Comparative Example 3-1, which used Comparative Example UDL-1 without a (B) metal source, showed that the pattern cross-section after substrate processing was not vertical, and LWR degradation was observed when the pattern was viewed from above. Comparative Example 3-3, which used Comparative Example UDL-3 containing metal nanoparticles, showed that the pattern cross-section after substrate processing was vertical, but LWR degradation was observed when the pattern was viewed from above. Comparative Example 3-4, which used Comparative Example Compound (RM-1) containing an organotin compound, showed that the pattern cross-section after substrate processing was not vertical, and LWR degradation was observed when the pattern was viewed from above. It is speculated that this is because the organotin compound (RM-1) has insufficient heat resistance and hardening properties, or the proportion of metal oxides contained in the resist underlayer film is low, resulting in insufficient improvement in dry etching resistance.

[0276] Accordingly, the metal-containing film-forming composition of the present invention can form a resist underlayer film with a high metal content, thus exhibiting excellent dry etching resistance compared to conventional organic resist underlayer films. Furthermore, it can provide a resist underlayer film material that simultaneously possesses a high level of filling / planarization characteristics that are difficult to achieve with conventional metal-containing resist underlayer films, making it very useful as a resist underlayer film material for use in multilayer resist methods.

[0277] This specification includes the following inventions.

[0278] [1]: A metal-containing film-forming composition comprising (A) a resin, (B) a metal source, and (C) an organic solvent, characterized in that: the (A) resin is a resin without phenolic hydroxyl groups, and the (B) metal source is a salt of a metal selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi with a carboxylic acid salt having a carbon number of 1 to 30 and a valence of 1 to 4, or a complex of the metal with a β-diketone.

[0279] [2]: The metal-containing film-forming composition as described in [1] above, wherein the (A) resin contains a crosslinking group selected from one or more of the following: substituted or unsubstituted vinyl, allyl, allyloxy, ethynyl, propynyl, propynyloxy, epoxy, and oxy-containing heterocyclic butyl.

[0280] [3]: The metal-containing film-forming composition as described in [1] or [2] above, wherein the (A) resin contains an aromatic ring, an alicyclic hydrocarbon, or a heteroaromatic ring, and contains a crosslinking group represented by the following formula (1), [Chemical 80] In the formula, * represents the bonding site with the aromatic ring, alicyclic hydrocarbon, or heteroaromatic ring, RA is a divalent organic group with 1 to 10 carbon atoms, RB is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, RC and RD represent any one of hydrogen atom, hydroxyl group, alkyl group with 1 to 10 carbon atoms, aryl group with 1 to 10 carbon atoms, or alkoxy group with 1 to 10 carbon atoms, and L is a divalent organic group with 1 to 10 carbon atoms.

[0281] [4]: A metal-containing film-forming composition as described in any of the above [1] to [3], wherein the (B) metal source is a salt of the metal and a carboxylic acid with a carbon number of 1 to 30 and a valence of 1 to 4.

[0282] [5]: A metal-containing film-forming composition as described in any of the above [1] to [4], wherein the (B) metal source is represented by the structure of the following formula (B-1), [Chemical 81] where M is selected from any of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi, R1 is a monovalent organic group with 1 to 30 carbon atoms, and n is an integer from 1 to 4.

[0283] [6]: A metal-containing film-forming composition as described in any of the above [1] to [5], wherein the metal source of (B) is Sn.

[0284] [7]: A metal-containing film-forming composition as described in any of the above [1] to [6], wherein the (A) resin has at least one constituent unit represented by the following general formula (G-1) to (G-5), [Chemical 82] wherein W1 and W2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the benzene ring and the naphthalene ring may also be replaced by hydrocarbon groups having 1 to 6 carbon atoms, Ra is represented by the following general formula (Z-1), Y is represented by the following general formula (Z-2), n1 is 0 or 1, n2 is 1 or 2, and V is independently represented by a hydrogen atom or a linking part, [Chemical 83] wherein Z1 is represented by the following general formula (Z-3), Ra is represented by the following general formula (Z-1), n4 is 0 or 1, n5 is 1 or 2, and V is independently represented by a hydrogen atom or a linking part. [Chem. 84] In formula, * indicates the bonding site with an oxygen atom, RB is a divalent organic group with 1 to 10 carbon atoms, and RA is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms. [Chem. 85] In formula, * indicates an atomic bond. [Chem. 86] In formula, * indicates an atomic bond, W1, W2, Y, and n1 are the same as above. [Chem. 87] In formula, m3 and m4 represent 1 or 2, Z is a single bond or any of the structures represented by the following general formula (Z-4), and Rx is any of the structures represented by the following general formula (Z-5). [Chem. 88] In formula, * indicates an atomic bond, l represents an integer from 0 to 3, Ra to Rf each independently represent a hydrogen atom or an alkyl, phenyl, or phenylethyl group with 1 to 10 carbon atoms that can also be fluorinated. Ra and Rb can also bond to form a cyclic compound. [Chem. 89] In formula, * indicates the bonding site with the aromatic ring, Q1 is a straight-chain saturated hydrocarbon group of 1 to 30 carbon atoms, or the structure represented by the following general formula (Z-6). [Chem. 90] In formula, * indicates the bonding site with the carbonyl group, Ra is the general formula (Z-1), Rj represents a straight-chain or branched hydrocarbon group, halogen atom, nitro group, amino group, nitrile group, alkoxy carbonyl group of 1 to 10 carbon atoms, or alkoxy group of 1 to 10 carbon atoms, h3 and h4 represent the number of substituents on the aromatic ring, each representing an integer from 0 to 7, however, h3+h4 is 0 to 7, and h5 represents 0 to 2. [Chem.91] In the formula, R1 refers to a saturated monovalent organic group with 1 to 30 carbons or an unsaturated monovalent organic group with 2 to 30 carbons, X refers to a divalent organic group with 1 to 30 carbons, Ra refers to the general formula (Z-1), p refers to an integer from 0 to 5, q1 refers to an integer from 1 to 6, p+q1 refers to an integer between 1 and 6, and q2 refers to 0 or 1.

[0285] [8]: A metal-containing film-forming composition as described in any of the above [1] to [7], wherein the composition further comprises one or more of (D) a crosslinking agent, (E) an acid generating agent, (F) a surfactant, and (G) a pigment.

[0286] [9]: The metal-containing film-forming composition of any one of [1] to [8] above, wherein the (C) organic solvent is 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 ((C') high-boiling solvent).

[0287]

[10] : A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by having the following steps: (I-1) coating a metal-containing film forming composition as described in any one of [1] to [9] above on the substrate to be processed, and then forming a metal-containing film by heat treatment; (I-2) forming a resist upper layer film on the metal-containing film using a photoresist material; (I-3) exposing the resist upper layer film to a pattern, and then developing it with a developer to form a pattern on the resist upper layer film; (I-4) using the resist upper layer film with the pattern formed as a mask, transferring the pattern onto the metal-containing film by dry etching; and (I-5) using the metal-containing film with the pattern formed as a mask, processing the substrate to form a pattern on the substrate to be processed.

[0288]

[11] : A pattern forming method, which is a method for forming a pattern on a substrate, characterized by comprising the following steps: (II-1) coating a metal-containing film forming composition as described in any one of [1] to [9] above onto the substrate, and then forming a metal-containing film by heat treatment; (II-2) forming a silicon resist intermediate film on the metal-containing film; (II-3) forming a resist upper layer film on the silicon resist intermediate film using a photoresist material; (II-4) ... After the upper resist film is exposed to a pattern, it is developed using a developer to form a pattern on the upper resist film. (II-5) The upper resist film with the pattern formed is used as a mask, and the pattern is transferred to the silicon-containing intermediate film using dry etching. (II-6) The silicon-containing intermediate film with the transferred pattern is used as a mask, and the pattern is transferred to the metal-containing film using dry etching. (II-7) The metal-containing film with the pattern formed is used as a mask, and the substrate is processed to form a pattern on the substrate.

[0289]

[12] : A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by comprising the following steps: (III-1) coating a metal-containing film forming composition as described in any one of [1] to [9] above onto the substrate to be processed, and then forming a metal-containing film by heat treatment; (III-2) forming an inorganic hard mask intermediate film selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film on the metal-containing film; (III-3) forming an organic thin film on the inorganic hard mask intermediate film; (III-4) applying photoresist on the organic thin film. (III-5) The resist upper layer film is formed by using materials to form a pattern. After the resist upper layer film is patterned, it is developed using a developer to form a pattern on the resist upper layer film. (III-6) The resist upper layer film with the pattern formed is used as a mask, and the pattern is transferred to the organic thin film and the inorganic hard mask intermediate film by dry etching. (III-7) The inorganic hard mask intermediate film with the transferred pattern is used as a mask, and the pattern is transferred to the metal-containing film by dry etching. (III-8) The metal-containing film with the pattern formed is used as a mask to process the substrate to form a pattern on the substrate.

[0290]

[13] : A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by comprising the following steps: (IV-1) coating a metal-containing film forming composition as described in any one of [1] to [9] above onto the substrate to be processed, and then forming a metal-containing film by heat treatment; (IV-2) forming an organic intermediate film on the metal-containing film; (IV-3) forming a silicon resist intermediate film, or a combination of an inorganic hard mask intermediate film and an organic thin film selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film, on the organic intermediate film; (IV-4) forming a resist upper layer film on the silicon resist intermediate film or the organic thin film using a photoresist material; (IV-5) forming a resist upper layer film on the silicon resist intermediate film or the organic thin film; (IV-6) forming a pattern forming composition as described in the above one of ... -5) After patterning the upper resist film, develop it with a developer to form a pattern on the upper resist film. (IV-6) Use the patterned upper resist film as a mask and transfer the pattern to the silicon resist intermediate film or the organic film and the inorganic hard mask intermediate film by dry etching. (IV-7) Use the patterned silicon resist intermediate film or the inorganic hard mask intermediate film as a mask and transfer the pattern to the organic intermediate film by dry etching. (IV-8) Use the organic intermediate film as a mask and transfer the pattern to the metal film by dry etching. (IV-9) Use the patterned metal film as a mask and process the substrate to form a pattern on the substrate.

[0291]

[14] : A pattern forming method, which is a method for forming a tone-reversed pattern on a substrate to be processed, characterized by having the following steps: (V-1) forming a resist lower layer film on the substrate to be processed; (V-2) forming a resist intermediate film or a combination of an inorganic hard mask intermediate film selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film and an organic thin film on the resist lower layer film; (V-3) forming a resist intermediate film or an inorganic hard mask intermediate film and an organic thin film on the resist intermediate film and an organic thin film. In the combination of organic thin films, a photoresist material is used to form the upper resist film. (V-4) After the upper resist film is patterned and exposed, it is developed using a developer to form a pattern on the upper resist film. (V-5) The patterned upper resist film is used as a mask, and the pattern is transferred to the intermediate resist film, or the organic thin film and the inorganic hard mask intermediate film, using dry etching. (V-6) The patterned intermediate resist film or the inorganic hard mask intermediate film is used as a mask. The pattern is transferred onto the resist underlayer film by dry etching. (V-7) After coating the resist underlayer film with the pattern formed with a metal-containing film-forming composition as described in any of [1] to [9] above, the metal-containing film is coated by heat treatment to fill the spaces between the resist underlayer film patterns with the metal-containing film. (V-8) The metal-containing film covering the resist underlayer film with the pattern formed is chemically stripped or dry-etched back to form the pattern. The top surface of the lower resist film is exposed. (V-9) The remaining intermediate resist film or hard mask intermediate film on the top surface of the lower resist film is removed by dry etching. (V-10) The lower resist film with the exposed surface pattern is removed by dry etching to form a reverse pattern of the original pattern composed of a metal-containing film. (V-11) The metal-containing film with the reverse pattern is used as a mask to process the substrate to form a reverse pattern on the substrate.

[0292]

[15] : As described in the pattern forming method in

[10] above, in step (I-3), the pattern is exposed using EUV light.

[0293]

[16] : The pattern forming method described above

[11] , wherein in step (II-4), the pattern is exposed using EUV light.

[0294]

[17] : The pattern forming method described above

[12] , wherein in step (III-5), the pattern is exposed using EUV light.

[0295]

[18] : As described in the pattern forming method in

[13] above, in step (IV-5), the pattern is exposed using EUV light.

[0296]

[19] : The pattern forming method described above

[14] , wherein in step (V-4), EUV light is used to expose the pattern.

[0297] Furthermore, the present invention is not limited to the above-described embodiments. The above-described embodiments are illustrative, and those having a structure substantially the same as the technical concept described in the claims of the present invention and performing the same effects are all covered by the technical scope of the present invention. [Simplified Explanation of the Diagram]

[0052] [Figure 1] Figures 1(A) to (F) are explanatory diagrams of an example of the pattern forming method of the present invention (3-layer resist treatment). [Figure 2] Figures 2(G) to (P) are explanatory diagrams of an example of the pattern forming method of the present invention (tonality reversal pattern forming method). [Figure 3] Figures 3(Q) to (S) are explanatory diagrams of a landfill characteristic evaluation method. [Figure 4] Figures 4(T) and (U) are explanatory diagrams of a flattening characteristic evaluation method.

Claims

1. A composition for forming a metal-containing film, comprising (A) a resin, (B) a metal source, and (C) an organic solvent, characterized in that: the (A) resin is a resin that does not contain phenolic hydroxyl groups but contains aromatic rings, alicyclic hydrocarbons, or heteroaromatic rings, and contains crosslinking groups represented by the following formula (1); and the (B) metal source is a salt of a metal selected from Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi with a carboxylic acid of 1 to 30 carbon atoms in a 1 to 4 valence, or a complex of the metal with a β-diketone. In the formula, * indicates the bonding site with an aromatic ring, alicyclic hydrocarbon, or heteroaromatic ring; RA represents a divalent organogroup with 1 to 10 carbon atoms; RB represents a hydrogen atom or a monovalent organogroup with 1 to 10 carbon atoms; RC and RD represent any one of a hydrogen atom, hydroxyl group, alkyl group with 1 to 10 carbon atoms, aryl group with 1 to 10 carbon atoms, or alkoxy group with 1 to 10 carbon atoms; and L represents a divalent organogroup with 1 to 10 carbon atoms.

2. As in claim 1, a metal-containing film-forming composition, wherein, The (B) metal source is a salt of the metal and a carboxylic acid with a carbon number of 1 to 30 and a valence of 1 to 4.

3. As in claim 1, a metal-containing film-forming composition, wherein, The structure represented by the metal source system (B-1) is as follows, where M is selected from any of Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, In, Sn, Hf, and Bi, R1 is a monovalent organic group with 1 to 30 carbon atoms, and n is an integer from 1 to 4.

4. As in claim 1, a metal-containing film-forming composition, wherein, The (B) metal source is of the Sn metal system.

5. The metal-containing film-forming composition as claimed in claim 1, wherein, The (A) resin has at least one constituent unit represented by the following general formulas (G-1) to (G-5), wherein W1 and W2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the benzene ring and naphthalene ring may be replaced by hydrocarbon groups having 1 to 6 carbon atoms; Ra is represented by the following general formula (Z-1); Y is represented by the following general formula (Z-2); n1 is 0 or 1; n2 is 1 or 2; and V independently represents a hydrogen atom or a linking part. In the following formula, Z1 is represented by the following general formula (Z-3); Ra is represented by the following general formula (Z-1); n4 is 0 or 1; n5 is 1 or 2; and V independently represents a hydrogen atom or a linking part. In the following formula, * represents a bonding site with an oxygen atom; RB is a divalent organic group having 1 to 10 carbon atoms; and RA is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. In the following formula, * represents an atomic bond. In the formula, * represents an atomic bond; W1, W2, Y, and n1 are the same as described above; m3 and m4 represent 1 or 2; Z is a single bond or any of the structures represented by the following general formula (Z-4); Rx is any of the structures represented by the following general formula (Z-5); in the formula, * represents an atomic bond; l represents an integer from 0 to 3; Ra~Rf each independently represent a hydrogen atom or an alkyl, phenyl, or phenylethyl group with 1 to 10 carbon atoms that may be substituted with fluorine; Ra and Rb may also bond to form a cyclic compound; in the formula, * represents the bonding site with an aromatic ring; Q1 is a straight-chain saturated hydrocarbon group of 1 to 30, or a structure represented by the following general formula (Z-6). In the formula, * indicates the bonding site with the carbonyl group, Ra is the general formula (Z-1), Rj represents a straight-chain or branched hydrocarbon group, halogen atom, nitro group, amino group, nitrile group, alkoxy carbonyl group with 1 to 10 carbons, or alkoxy group with 1 to 10 carbons, h3 and h4 represent the number of substituents on the aromatic ring, each representing an integer from 0 to 7, except that h3+h4 is 0 to 7, and h5 represents 0 to 2. In the formula, R1 is a saturated monovalent organogroup with 1 to 30 carbons or an unsaturated monovalent organogroup with 2 to 30 carbons, X is a divalent organogroup with 1 to 30 carbons, Ra is the general formula (Z-1), p is an integer from 0 to 5, q1 is an integer from 1 to 6, p+q1 is an integer from 1 to 6, and q2 is 0 or 1.

6. The metal-containing film-forming composition as claimed in claim 1, wherein, The composition further includes one or more of (D) crosslinking agent, (E) acid generating agent, (F) surfactant, and (G) pigment.

7. The metal-containing film-forming composition as claimed in claim 1, wherein, The (C) organic solvent is 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 more than 180°C ((C') high-boiling solvents).

8. A pattern forming method for forming a pattern on a substrate, characterized by comprising the following steps: (I-1) coating a metal-containing film forming composition as claimed in any one of claims 1 to 7 on the substrate to be processed, and then forming a metal-containing film by heat treatment; (I-2) forming a resist upper layer film on the metal-containing film using a photoresist material; (I-3) exposing the resist upper layer film to a pattern, and then developing it using a developer to form a pattern on the resist upper layer film; (I-4) using the patterned resist upper layer film as a mask, transferring the pattern onto the metal-containing film by dry etching; and (I-5) using the patterned metal-containing film as a mask, processing the substrate to form a pattern on the substrate to be processed.

9. A pattern forming method for forming a pattern on a substrate, characterized by comprising the following steps: (II-1) coating a metal-containing film forming composition as claimed in any one of claims 1 to 7 onto the substrate, and then forming a metal-containing film by heat treatment; (II-2) forming a silicon-containing resist intermediate film on the metal-containing film; (II-3) forming a resist upper layer film on the silicon-containing resist intermediate film using a photoresist material; (II-4) exposing the resist upper layer film to a pattern, and then developing it with a developer to form a pattern on the resist upper layer film; (II-5) using the patterned resist upper layer film as a mask, and transferring the pattern onto the silicon-containing resist intermediate film by dry etching. (II-6) Using the silicon resist intermediate film with the transferred pattern as a mask, the pattern is transferred onto the metal film by dry etching, and (II-7) Using the metal film with the formed pattern as a mask, the substrate to be processed is processed to form a pattern on the substrate.

10. A pattern forming method for forming a pattern on a substrate being processed, characterized by comprising the following steps: (III-1) coating a metal-containing film forming composition as claimed in any one of claims 1 to 7 onto the substrate being processed, and then forming a metal-containing film by heat treatment; (III-2) forming an inorganic hard mask intermediate film selected from silicon oxide film, silicon nitride film, and silicon oxynitride film on the metal-containing film; (III-3) forming an organic thin film on the inorganic hard mask intermediate film; (III-4) forming a resist upper layer film on the organic thin film using a photoresist material; (III-5) exposing the resist upper layer film to a pattern, and then developing it with a developer to form a pattern on the resist upper layer film; (III-6) using the patterned resist upper layer film as a mask, and transferring the pattern onto the organic thin film and the inorganic hard mask intermediate film by dry etching. (III-7) Using the inorganic hard mask intermediate film with the transferred pattern as a mask, the pattern is transferred onto the metal-containing film by dry etching, and (III-8) Using the metal-containing film with the formed pattern as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed.

11. A pattern forming method for forming a pattern on a substrate being processed, characterized by comprising the following steps: (IV-1) coating a metal-containing film forming composition as claimed in any one of claims 1 to 7 onto the substrate being processed, and then forming a metal-containing film by heat treatment; (IV-2) forming an organic intermediate film on the metal-containing film; (IV-3) forming a silicon resist-containing intermediate film, or a combination of an inorganic hard mask intermediate film and an organic thin film selected from silicon oxide film, silicon nitride film, and silicon oxynitride film, on the organic intermediate film; (IV-4) forming a resist upper layer film using a photoresist material on the silicon resist-containing intermediate film or the organic thin film; (IV-5) after pattern exposure of the resist upper layer film, developing it with a developer to form a pattern on the resist upper layer film. (IV-6) Using the patterned resist top film as a mask, the pattern is transferred to the silicon resist intermediate film or the organic film and the inorganic hard mask intermediate film by dry etching. (IV-7) Using the patterned silicon resist intermediate film or the inorganic hard mask intermediate film as a mask, the pattern is transferred to the organic intermediate film by dry etching. (IV-8) Using the organic intermediate film as a mask, the pattern is transferred to the metal film by dry etching. (IV-9) Using the patterned metal film as a mask, the substrate is processed to form a pattern on the substrate.

12. A pattern forming method for forming a tone-reversed pattern on a substrate being processed, characterized by comprising the following steps: (V-1) forming a lower resist film on the substrate being processed; (V-2) forming a resist intermediate film or a combination of an inorganic hard mask intermediate film and an organic thin film selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film on the lower resist film; (V-3) forming a resist upper film on the resist intermediate film or the combination of inorganic hard mask intermediate film and organic thin film using a photoresist material; (V-4) exposing the resist upper film to a pattern and developing it with a developer to form a pattern on the resist upper film; (V-5) using the patterned resist upper film as a mask, transferring the pattern onto the resist intermediate film, or the organic thin film and the inorganic hard mask intermediate film, by dry etching. (V-6) Using the resist interlayer film or inorganic hard mask interlayer film with the transferred pattern as a mask, the pattern is transferred onto the resist underlayer film by dry etching. (V-7) After coating the resist underlayer film with the pattern formed with a metal-containing film-forming composition as described in any of claims 1 to 7, the metal-containing film is coated by heat treatment, and the patterns in the resist underlayer film are filled with the metal-containing film. (V-8) The metal-containing film covering the resist underlayer film with the pattern formed is chemically stripped or dry-etched back to expose the top surface of the resist underlayer film with the pattern formed. (V-9) The resist interlayer film or hard mask interlayer film remaining on the top surface of the resist underlayer film is removed by dry etching. (V-10) The resist underlayer film with the pattern formed on the exposed surface is removed by dry etching to form a reversed pattern of the original pattern composed of a metal-containing film. (V-11) The metal-containing film with the inverted pattern is used as a mask to process the substrate to form an inverted pattern on the substrate.

13. The pattern forming method as described in claim 8, wherein, In this step (I-3), the pattern is exposed using EUV light.

14. The pattern forming method as described in claim 9, wherein, In this step (II-4), the pattern is exposed using EUV light.

15. The pattern forming method as described in claim 10, wherein, In step (III-5), the pattern is exposed using EUV light.

16. The pattern forming method as described in claim 11, wherein, In this step (IV-5), the pattern is exposed using EUV light.

17. The pattern forming method as described in claim 12, wherein, In this step (V-4), the pattern is exposed using EUV light.

Images