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

Abstract

The invention relates to a compound for forming a metal-containing film, a composition for forming a metal-containing film, and a pattern forming method. The present invention addresses the problem of providing: a compound for forming a metal-containing film, which has excellent dry etching resistance and also has a high degree of film-forming properties and landfill properties and a high tin content; a composition for forming a metal-containing film, which uses the compound; and a pattern forming method in which the composition is used as a resist underlayer film material. This problem is solved by a metal-containing compound for forming a film, which is characterized in that the compound is a polymer containing either or both of repeating units represented by general formula (P-1) or (P-2). [chemical] # imgabs0 #

Description

Technical Field

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

[0002] With the high integration and high speed of LSIs, the miniaturization of pattern rules has been rapidly progressing. Regarding the most advanced miniaturization technology, ArF immersion lithography is used in mass production of devices below the 45 nm node. Also, double exposure (double patterning) processing can be put into practical use in the next generation below the 28 nm node together with ArF immersion exposure, and a narrow pitch pattern beyond the optical limit can be formed.

[0003] In addition, in device manufacturing below the 20 nm node, discussions on multiple exposure (multiple patterning) processing for fabricating a narrower pitch pattern by repeating exposure and etching three or more times have been underway. However, due to an increase in the number of steps in multiple exposure processing, it is necessary to directly face the situation of reduced productivity and a significant increase in cost due to the lengthening of the manufacturing period and an increase in the frequency of defect generation.

[0004] In recent years, as a promising technology to replace and combine the use of ArF immersion lithography and multiple exposure processing, extreme ultraviolet (EUV) lithography with a wavelength of 13.5 nm has attracted attention. By using this technology, a fine pattern with a half pitch of 25 nm or less can be formed in one exposure.

[0005] On the other hand, in EUV lithography, in order to make up for the insufficient output of the light source, high sensitivity of the resist material is strongly required. However, an increase in shot noise is closely related to an increase in the line edge roughness (LER, LWR) accompanying high sensitivity, and one of the important issues in EUV lithography is to achieve both high sensitivity and low edge roughness.

[0006] In an attempt to increase the sensitivity of the resist and reduce the influence of shot noise, in recent years, the use of metal materials in resist materials has been discussed. Compounds containing metal elements such as barium, titanium, hafnium, zirconium, and tin have a higher absorbance of EUV light than metal-free organic materials, and an improvement in the photosensitivity of the resist and suppression of the influence of shot noise can be expected. Also, a metal-containing resist pattern can be expected to have a high selectivity in etching by combining it with an underlying film made of a non-metal material.

[0007] For example, there has been a discussion on resist materials containing metal salts and organometallic complexes described in Patent Documents 1 and 2, or non-chemically amplified resist materials using metal oxide nanoparticles described in Patent Documents 3 and 4.

[0008] Among them, tin-containing molecules have been actively studied because of their excellent absorption of electron beams and extreme ultraviolet rays. In the case of organotin polymers, which are one of them, alkyl ligands dissociate due to light absorption or secondary electrons generated thereby, and negative tone patterning that cannot be removed by an organic developing solution can be performed through crosslinking with oxygenated groups of surrounding chains. Such organotin polymers can improve sensitivity while maintaining resolution and line edge roughness, but have not yet reached the commercial level (Patent Document 5). Also, there are many problems such as insufficient storage stability of the change in resist sensitivity.

[0009] Regarding the above problems, the development of materials containing metal elements such as titanium, hafnium, zirconium, and tin has also been explored for use in the resist underlayer film. By using a metal-containing resist material, it is not necessary to improve performance such as exposure sensitivity, which is a problem, and suppress the change in sensitivity in the storage environment, and by containing the above metal elements, it is possible to provide a resist underlayer film with excellent dry etching resistance. Patent Document 7 reports that a material using a Ti compound exhibits excellent dry etching resistance against CHF3 / CF4-based gases and CO2 / N2-based gases.

[0010] On the other hand, regarding the problems when using a metal compound in the resist underlayer film, film-forming properties and filling properties can be cited. For example, in a compound expected to be applied under a photoresist as in Patent Document 6, heat resistance is not mentioned, and since baking at a high temperature is not expected, the heat resistance is insufficient, and there are concerns about poor filling and film-forming properties. Also, Patent Document 7 does not mention film-forming properties and filling properties, but generally, metal oxide compounds have a large thermal shrinkage during baking, and after high-temperature baking, the filling properties deteriorate significantly. Therefore, there are concerns that it is not sufficient as a resist underlayer film material that requires heat-resistant properties such as film-forming properties and filling characteristics. Patent Document 8 reports that a metal compound modified with a specific ligand has excellent filling properties, but the baking temperature for the filling property evaluation performed is a low temperature of 150 °C, and there are concerns that it is not sufficient for a resist underlayer film that requires heat resistance (for example, characteristics for heat treatment that may be applied after forming the resist underlayer film). Patent Document 9 provides a resist underlayer film material with excellent filling properties after baking at 400 °C by mixing the metal compound reported in Patent Document 8 with an organic polymer having a specific structure. However, since it is a mixed composition of a metal compound as an inorganic substance and a polymer as an organic substance, there are concerns such as poor film formation, deterioration of storage stability, and deterioration of dry etching resistance caused by poor compatibility.

[0011] Prior Art Documents

[0012] Patent Documents

[0013] [Patent Document 1] Japanese Patent No. 5708521 Gazette

[0014] [Patent Document 2] Japanese Patent Publication No. 5708522

[0015] [Patent Document 3] US Patent No. 9310684 Specification

[0016] [Patent Document 4] US Patent Application Publication No. 2017 / 0102612 Specification

[0017] [Patent Document 5] Japanese Patent Publication No. 2021-162865

[0018] [Patent Document 6] Japanese Patent Publication No. 7028940

[0019] [Patent Document 7] Japanese Patent Publication No. 6189758

[0020] [Patent Document 8] Japanese Patent Publication No. 7050137

[0021] [Patent Document 9] Japanese Patent Publication No. 2022-521531 SUMMARY OF THE INVENTION

[0022] [Problems to be Solved by the Invention]

[0023] In view of the above circumstances, the present invention aims to provide a metal-containing film-forming compound that has excellent dry etching resistance to known organic underlayer film materials, and at the same time has a high degree of film-forming property, filling property, and a relatively high tin content rate, a metal-containing film-forming composition using the compound, and a patterning method using the composition as an underlayer film material for a resist.

[0024] [Means for Solving the Problems]

[0025] In order to solve the above problems, the present invention provides a metal-containing film-forming compound, characterized in that the compound is a polymer containing any one or both of the repeating units represented by the following general formula (P-1) or (P-2).

[0026] [Chemical Formula 1]

[0027]

[0028] In the general formulas (P-1) and (P-2) above, R1 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. W1 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms, and the hydrocarbon group contains oxygen atom, nitrogen atom, sulfur atom as heteroatoms, and can also form an ether bond, a carbonyl group, an ester group, an amide group, and can also form a heterocyclic structure with the heteroatoms spaced apart. R2 represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms containing one or more double bonds or triple bonds, a hydroxyl group, an amino group, a halogen atom, s1 is an integer of 0 to 1, and n1 is an integer of 0 to 1. Also, these elements in the repeating unit may include a variety of different ones. W2 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms, and the hydrocarbon group contains oxygen atom, nitrogen atom, sulfur atom as heteroatoms, and can also form an ether bond, a carbonyl group, an ester group, an acylamino group, and can also form a heterocyclic structure with the heteroatoms spaced apart. s2 is an integer of 0 to 1. s3 is 1 or 2. When s3 is 1, R3 is a hydrogen atom or a hydrocarbon group having a hydroxyl group and 1 to 10 carbon atoms. When s3 is 2, R3 is an oxygen atom, and together with the carbon atom to which it is bonded, it forms a carbonyl group. W2 and R3 may also bond to each other to form a ring structure. Also, these elements in the repeating unit may include a variety of different ones.

[0029] In the case of a polymer containing such a repeating unit, radicals are generated due to the radical cleavage of the Sn-alkyl bond, so a crosslinking reaction caused by the radicals is induced. Also, since it is a polymer containing a repeating unit, considering the low possibility of immediately converting to a small molecular weight decomposition product that can sublime when the bond is broken, and it can participate in the crosslinking reaction before sublimation, it becomes a compound with excellent heat resistance, and can suppress the deterioration of film-forming properties and landfill properties. Therefore, a resist underlayer film material with excellent film-forming properties and landfill characteristics even after high-temperature baking can be provided. Also, since at least one tin atom is contained in the repeating unit, the tin content rate is high. If the organic groups of the repeating unit are designed densely, the Sn content rate can be further increased, and a resist underlayer film material with excellent etching resistance can be provided.

[0030] Among the above compounds, it is preferably (i) a polymer containing a repeating unit represented by the aforementioned general formula (P-1), and in the aforementioned general formula (P-1), W1 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms which may also contain a hydroxyl group or an amino group (the aforementioned hydrocarbon group contains an oxygen atom, a nitrogen atom, a sulfur atom, and may also form an ether bond, a carbonyl group, an ester group), or is any one of the groups represented by the following general formulas (W1-1) to (W1-4).

[0031] [Chemical formula 2]

[0032]

[0033] In the above general formulas (W1-1) to (W1-4), R W is a divalent organic group having 1 to 23 carbon atoms, #1 represents the bonding part with the ester, and #2 represents the bonding part with the benzene ring.

[0034] Furthermore, among the above compounds, it is preferably (ii) a polymer containing a repeating unit represented by the aforementioned general formula (P-2), and in the aforementioned general formula (P-2), W2 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms which may also contain a hydroxyl group or an amino group, or is a cyclic hydrocarbon group formed by bonding with R3 (the aforementioned hydrocarbon group contains an oxygen atom, a nitrogen atom, a sulfur atom, and may also form an ether bond, a carbonyl group, an ester group), or is any one of the groups represented by the following general formulas (W2-1) to (W2-4).

[0035] [Chemical formula 3]

[0036]

[0037] In the above general formulas (W2-1) to (W2-4), R W is a divalent organic group having 1 to 23 carbon atoms, and #1 and #2 respectively represent the bonding parts with the ester and the carbon atom.

[0038] If W1 in the above general formula (P-1) and / or W2 in (P-2) has the above structure, the ratio of the organic groups in the repeating unit can be suppressed, and the tin content rate can be increased.

[0039] Furthermore, R in the above general formulas (W1-1) to (W1-4) of (i) and / or the general formulas (W2-1) to (W2-4) of (ii) W is preferably an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

[0040] R in the above general formulas (W1-1) to (W1-4) and (W2-1) to (W2-4) W If it is an unsaturated hydrocarbon group having 2 to 23 carbon atoms, the thermosetting property of the above polymer can be further improved.

[0041] Further, in the present invention, the aforementioned R in the general formulas (W1-1) to (W1-4) of the above (i) and / or the general formulas (W2-1) to (W2-4) of the above (ii) W may be a group represented by the following general formula (1).

[0042] [Chemical Formula 4]

[0043]

[0044] In the aforementioned general formula (1), R a , R b and R c are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and R a and R b may also be bonded to form a cyclic substituent. *1 and *2 respectively represent the bonding parts to the carbonyl group, and *1 and *2 may also be inverted.

[0045] In the above general formulas (W1-1) to (W1-4) and (W2-1) to (W2-4), if R W is a group represented by the above general formula (1), it may have both thermosetting properties and a high tin content rate. When it is used in a metal-containing film-forming composition, it can provide a resist underlayer film material that exhibits better film-forming - filling properties and tin content rate.

[0046] Further, it is preferable that the terminal structure of the polymer having the repeating unit of the aforementioned general formula (P-1) is the following general formula (T-1), or the terminal structure of the polymer having the repeating unit of the aforementioned general formula (P-2) is the following general formula (T-2).

[0047] [Chemical Formula 5]

[0048]

[0049] In the above general formulas (T-1) to (T-2), R1, R2, R3, W1, W2, s1, s2 and s3 are the same as those in the above general formulas (P-1) to (P-2).

[0050] If the terminal structures of the polymers having the repeating units of the above general formula (P-1) or (P-2) are the above general formulas (T-1) or (T-2) respectively, the repeating units and the terminal structures all contain tin atoms, so the tin content rate can be increased. Further, the tin-alkyl bond generates free radicals due to heat, so the crosslinking reaction is promoted by these free radicals. Therefore, the thermosetting property can also be increased, and thus the sublimates can be suppressed, and the volume shrinkage that causes deterioration of the filling property can also be expected to be suppressed. Thereby, a resist underlayer film material having excellent film-forming properties, filling properties and etching resistance after high-temperature baking can be provided.

[0051] Furthermore, the terminal structure of the polymer having the repeating unit of the aforementioned general formula (P-1) or (P-2) is *-OC(=O)R, where R is a monovalent organic group, and * represents the bonding portion with the Sn atom in the polymer, which is preferable.

[0052] When the terminal structure of the polymer having the repeating unit of the aforementioned general formula (P-1) or (P-2) is *-OC(=O)R, where R is a monovalent organic group, and * represents the bonding portion with the Sn in the polymer; since R can be freely changed, if a bulky structure is incorporated, improvement in solubility can be expected. In addition, a crosslinked structure can be formed, so sublimates can be further suppressed, and volume shrinkage that causes deterioration of landfill properties can also be expected to be suppressed. Thereby, a resist underlayer film material having excellent film-forming properties and landfill characteristics even after high-temperature baking can be provided.

[0053] At this time, R in the aforementioned terminal structure *-OC(=O)R is preferably any one of the groups represented by the following general formulae (A-1) to (A-4), the following general formula (3), and the following general formula (4).

[0054] [Chemical formula 6]

[0055]

[0056] In the aforementioned general formulae (A-1) to (A-4), Y A1 , Y A2 may be the same or different from each other, and is a substituted or unsubstituted divalent organic group having 1 to 23 carbon atoms and being saturated or having 2 to 23 carbon atoms and being unsaturated, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkylene group having 7 to 31 carbon atoms. R A is a hydrogen atom, a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms and being saturated or having 2 to 20 carbon atoms and being unsaturated, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. R A1 is an organic group in which a protecting group detaches due to the action of any one or both of an acid and heat to generate one or more hydroxyl groups or carboxyl groups, and * represents the bonding portion with the carbonyl group.

[0057] [Chemical formula 7]

[0058]

[0059] In the aforementioned general formula (2), R A2 is an organic group in which a protecting group detaches due to the action of any one or both of an acid and heat, and * represents the bonding portion with Y A1 or Y A2 .

[0060] [Chemical formula 8]

[0061]

[0062] In the general formula (3) above, X is a divalent organic group having 1 to 31 carbon atoms, B is the following general formula (B), and * represents the bonding part to the carbonyl group.

[0063] [Chemical formula 9]

[0064] B = *-Y B -R B (B)

[0065] In the general formula (B) above, Y B is a saturated divalent organic group having 1 to 20 carbon atoms with or without substitution, an unsaturated divalent organic group having 2 to 20 carbon atoms with or without substitution, a divalent arylene group having 6 to 30 carbon atoms with or without substitution, or a divalent arylalkylene group having 7 to 31 carbon atoms with or without substitution, and R B is a hydroxyl group or any one of the structures represented by the following general formulas (B-1) to (B-3).

[0066] [Chemical formula 10]

[0067]

[0068] In the general formulas (B-1) to (B-3) above, R B1 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents the bonding part to Y B .

[0069] [Chemical formula 11]

[0070]

[0071] In the general formula (4) above, X is a divalent organic group having 1 to 31 carbon atoms, C is any one of the groups represented by the following general formulas (C-1) to (C-4), and * represents the bonding part to the carbonyl group.

[0072] [Chemical formula 12]

[0073]

[0074] In the general formulas (C-1) and (C-3) above, R C1 is a hydrogen atom or a methyl group, and they may be the same or different from each other in the same formula. In (C-3) and (C-4), R C2 is a hydrogen atom or a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms with or without substitution (such as an aliphatic hydrocarbon group), an aryl group having 6 to 30 carbon atoms with or without substitution, or an arylalkyl group having 7 to 31 carbon atoms with or without substitution. * represents the bonding part to the carbonyl group.

[0075] When R is a structure represented by the above general formula (A-1) to (A-4), since the structure contains a bulky organic group in which the protecting group detaches due to the action of either or both of acid and heat, the solvent solubility of the polymer can be improved. In addition, when it is used in a metal-containing film-forming composition, the protecting group detaches during baking to generate a hydroxyl group and a carboxyl group. The α-hydrogen of the resulting OH and carboxylic acid easily reacts with the free radicals generated by the cleavage of the tin-carbon bond during baking and causes a crosslinking reaction. Therefore, the compound of the present invention has excellent thermosetting properties and can suppress the volume shrinkage that causes deterioration of film-forming properties and filling properties. In addition, a resist underlayer film material with excellent film-forming properties and filling characteristics even during high-temperature baking can be provided.

[0076] Furthermore, when R is a structure represented by the above general formula (3), the terminal contains a hydroxyl group or any one of the crosslinking groups in the structures represented by the above general formula (B-1) to (B-3). Therefore, when they are used in a metal-containing film-forming composition, not only the crosslinking reaction of free radicals generated by the cleavage of the tin-carbon bond during baking, but also the reaction of free radicals with crosslinking groups and the reaction between crosslinking groups themselves can cause a further crosslinking reaction. Thus, it has excellent thermosetting properties, can suppress the volume shrinkage that causes deterioration of film-forming properties and filling properties, and can provide a resist underlayer film material with excellent film-forming properties and filling characteristics even after high-temperature baking.

[0077] Moreover, when R is a structure represented by the above general formula (4), the terminal contains any one of the structures represented by (C-1) to (C-4). Since the crosslinking group density of the aforementioned structure is high and the thermosetting property is excellent, when it is used in a metal-containing film-forming composition, the volume shrinkage during baking is small, and a resist underlayer film material with excellent film-forming properties and filling characteristics even after high-temperature baking can be provided.

[0078] Y in the above general formula (A-1) to (A-4) A1 、X in the aforementioned general formula (3), or X in the aforementioned general formula (4) is preferably an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

[0079] Y in the above general formula (A-1) to (A-4) A1 、If X in the above general formula (3) or X in the above general formula (4) is an unsaturated hydrocarbon having 2 to 23 carbon atoms, the thermosetting property of the above metal-containing film-forming compound can be further improved.

[0080] At this time, Y in the above general formula (A-1) to (A-4) A1 、X in the above general formula (3), or X in the above general formula (4) can be a group represented by the following general formula (1).

[0081] [Chemical formula 13]

[0082]

[0083] In the above general formula (1), R a , R b and R c are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R a and R b may also be bonded to form a cyclic substituent. *1 and *2 respectively represent the bonding parts to the carbonyl group, and *1 and *2 may also be reversed.

[0084] When Y in the above general formulas (A-1) to (A-4) A1 , X in the above general formula (2), or X in the above general formula (3) is represented by the above general formula (1), the thermosetting property can be improved. When it is used in a metal-containing film-forming composition, a resist underlayer film material having better film-forming properties and filling characteristics can be provided.

[0085] Furthermore, the present invention provides a metal-containing film-forming composition, which is a metal-containing film-forming composition that functions as a resist underlayer film material used in semiconductor manufacturing, and is characterized by containing:

[0086] (a) The metal-containing film-forming compound of the present invention, and

[0087] (b) An organic solvent.

[0088] If it is such a metal-containing film-forming composition, since it contains an organotin compound having excellent solvent solubility and heat resistance, a resist underlayer film material having excellent dry etching resistance to known organic underlayer film materials and high film-forming properties at the same time can be provided.

[0089] The above composition is a metal-containing film-forming composition that can be used as a resist underlayer film used in the multilayer resist method, and may further contain one or more of (c) a crosslinking agent, (d) a surfactant, (e) a fluidity promoter, and (f) an acid generator.

[0090] Furthermore, it is preferable that the above (b) organic solvent is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher.

[0091] By adding a high-boiling solvent to the above metal-containing film-forming compound to impart thermal fluidity, the planarization characteristics of the metal-containing film-forming composition can be further improved.

[0092] Furthermore, the present invention provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed, and is characterized by having the following steps:

[0093] (I-1) After coating the metal-containing film-forming composition of the present invention on the substrate to be processed, heat treatment is performed to form a metal-containing film.

[0094] (I-2) An upper resist film is formed on the aforementioned metal-containing film using a photoresist material.

[0095] (I-3) After pattern exposure of the aforementioned upper resist film, development is carried out with a developer, and a pattern is formed on the aforementioned upper resist film.

[0096] (I-4) Using the aforementioned patterned upper resist film as a mask, the pattern is transferred to the aforementioned metal-containing film by dry etching, and

[0097] (I-5) Using the aforementioned patterned metal-containing film as a mask, the substrate to be processed is processed, and a pattern is formed on the aforementioned substrate to be processed.

[0098] With the pattern formation method using the above two-layer resist process, a fine pattern can be formed on the object to be processed (substrate to be processed).

[0099] Furthermore, the present invention provides a pattern formation method, which is a method for forming a pattern on a substrate to be processed, and is characterized by having the following steps:

[0100] (II-1) After coating the metal-containing film-forming composition of the present invention on the substrate to be processed, heat treatment is performed to form a metal-containing film.

[0101] (II-2) A resist intermediate film is formed on the aforementioned metal-containing film.

[0102] (II-3) An upper resist film is formed on the aforementioned resist intermediate film using a photoresist material.

[0103] (II-4) After pattern exposure of the aforementioned upper resist film, development is carried out with a developer, and a pattern is formed on the aforementioned upper resist film.

[0104] (II-5) Using the aforementioned patterned upper resist film as a mask, the pattern is transferred to the aforementioned resist intermediate film by dry etching.

[0105] (II-6) Using the aforementioned resist intermediate film with the transferred pattern as a mask, the pattern is transferred to the aforementioned metal-containing film by dry etching, and

[0106] (II-7) Using the aforementioned patterned metal-containing film as a mask, the substrate to be processed is processed, and a pattern is formed on the aforementioned substrate to be processed.

[0107] The pattern formation method using the above three-layer resist process can form fine patterns on a workpiece with high precision.

[0108] Furthermore, the present invention provides a pattern formation method, which is a method for forming a pattern on a workpiece substrate, and is characterized by having the following steps:

[0109] (III-1) After coating the metal-containing film-forming composition of the present invention on the workpiece substrate, heat treatment is performed to form a metal-containing film.

[0110] (III-2) An inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the aforementioned metal-containing film.

[0111] (III-3) An organic thin film is formed on the aforementioned inorganic hard mask intermediate film.

[0112] (III-4) A resist upper layer film is formed on the aforementioned organic thin film using a photoresist material.

[0113] (III-5) After pattern exposure of the aforementioned resist upper layer film, development is performed with a developer, and a pattern is formed on the aforementioned resist upper layer film.

[0114] (III-6) Using the aforementioned patterned resist upper layer film as a mask, the pattern is transferred to the aforementioned organic thin film and the aforementioned inorganic hard mask intermediate film by dry etching.

[0115] (III-7) Using the aforementioned patterned inorganic hard mask intermediate film as a mask, the pattern is transferred to the aforementioned metal-containing film by dry etching, and

[0116] (III-8) Using the aforementioned patterned metal-containing film as a mask, the aforementioned workpiece substrate is processed, and a pattern is formed on the aforementioned workpiece substrate.

[0117] The pattern formation method using the above four-layer resist process can form fine patterns on a workpiece with high precision.

[0118] At this time, it is preferable to form the aforementioned inorganic hard mask intermediate film by CVD method or ALD method.

[0119] If the aforementioned inorganic hard mask is formed by CVD method or ALD method, fine patterns can be formed on a workpiece with higher precision.

[0120] Furthermore, the present invention provides a pattern formation method, which is a method for forming a pattern on a workpiece substrate, and is characterized by having the following steps:

[0121] (IV-1) A resist lower layer film is formed on the workpiece substrate.

[0122] (IV-2) After coating the metal-containing film-forming composition of the present invention on the aforementioned resist underlayer film, heat treatment is performed to thereby form a metal-containing film.

[0123] (IV-3) On the aforementioned metal-containing film, a resist upper layer film is formed using a photoresist material, or an organic adhesion film is formed by spin coating on the aforementioned metal-containing film, and a resist upper layer film is formed thereon using a photoresist material.

[0124] (IV-4) After pattern exposure of the aforementioned resist upper layer film, development is performed with a developer, and a pattern is formed on the aforementioned resist upper layer film.

[0125] (IV-5) Using the aforementioned patterned resist upper layer film as a mask, the pattern is transferred to the aforementioned metal-containing film, or the aforementioned organic adhesion film and the aforementioned metal-containing film by dry etching.

[0126] (IV-6) Using the aforementioned metal-containing film with the transferred pattern as a mask, the pattern is transferred to the aforementioned resist underlayer film, and

[0127] (IV-7) Using the aforementioned patterned resist underlayer film as a mask, the aforementioned substrate to be processed is processed, and a pattern is formed on the aforementioned substrate to be processed.

[0128] With the pattern formation method using the above multi-layer resist process, a fine pattern can be formed on the object to be processed with high precision.

[0129] Furthermore, the present invention provides a pattern formation method, which is a method for forming a pattern on a substrate to be processed, and is characterized by having the following steps:

[0130] (V-1) A resist underlayer film is formed on the substrate to be processed.

[0131] (V-2) A resist intermediate film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film and an organic thin film is formed on the aforementioned resist underlayer film.

[0132] (V-3) On the aforementioned resist intermediate film, or on the combination of the inorganic hard mask intermediate film and the organic thin film, a resist upper layer film is formed using a photoresist material.

[0133] (V-4) After pattern exposure of the aforementioned resist upper layer film, development is performed with a developer, and a pattern is formed on the aforementioned resist upper layer film.

[0134] (V-5) Using the aforementioned patterned resist upper layer film as a mask, the pattern is transferred to the aforementioned resist intermediate film, or the aforementioned organic thin film and the aforementioned inorganic hard mask intermediate film by dry etching.

[0135] (V-6) Using the resist intermediate film or inorganic hard mask intermediate film with the transferred pattern as a mask, and transferring the pattern to the resist lower layer film by dry etching.

[0136] (V-7) Coating the composition for forming a metal-containing film of the present invention on the patterned resist lower layer film and then performing heat treatment, thereby coating a metal-containing film and filling the space between the patterns of the resist lower layer film with the metal-containing film.

[0137] (V-8) Etching back the metal-containing film covering the patterned resist lower layer film by chemical stripping or dry etching, and exposing the top surface of the patterned resist lower layer film.

[0138] (V-9) Removing the resist intermediate film or hard mask intermediate film remaining on the top surface of the resist lower layer film by dry etching.

[0139] (V-10) Removing the patterned resist lower layer film with the exposed surface by dry etching, and forming an inverted pattern of the original pattern on the metal-containing film, and

[0140] (V-11) Using the metal-containing film with the formed inverted pattern as a mask to process the substrate to be processed, and forming an inverted pattern on the substrate to be processed.

[0141] The pattern forming method using the above inversion process can form fine patterns on the object to be processed with further higher precision.

[0142] At this time, it is also advisable to use the CVD method or ALD method to form the above inorganic hard mask intermediate film.

[0143] If the above inorganic hard mask is formed by the CVD method or ALD method, fine patterns can be formed on the object to be processed with higher precision.

[0144] [Effects of the Invention]

[0145] As described above, the metal-containing film-forming compound of the present invention is a polymer containing repeating units represented by the above general formulas (P-1) to (P-2), and generates radicals due to the radical cleavage of the Sn-alkyl bond, so it will cause a crosslinking reaction caused by these radicals. Also, since it is a polymer containing repeating units, considering the low possibility of immediately converting into a small-molecular-weight decomposition product that can sublime when the bond is cut, it can participate in the crosslinking reaction before decomposition and sublimation, so it becomes a compound with excellent heat resistance and can suppress volume shrinkage that causes deterioration of film-forming properties and landfill properties. Therefore, it is possible to provide a resist underlayer film material with excellent film-forming properties and landfill characteristics even after high-temperature baking. Also, since at least one tin atom is contained in the repeating unit, the tin content rate is high. If the organic groups of the repeating unit are designed densely, the Sn content rate can be further increased, and a resist underlayer film material with excellent etching resistance can be provided.

[0146] In particular, in the fine patterning process using the multilayer resist method in the semiconductor device manufacturing process, even on a processed substrate having a high aspect ratio fine pattern structure such as a dense portion of a DRAM memory where miniaturization has progressed and having a portion difficult to fill / planarize, it can be filled without generating defects such as voids and peeling. Also, compared with known coating-type organic resist underlayer film materials, it has excellent dry etching resistance, so a finer pattern can be formed on the processed body with higher precision than an organic resist underlayer film.

[0147] Also, the metal-containing film-forming composition containing the metal-containing film-forming compound of the present invention has the following characteristics: Since it contains tin atoms with a large EUV light absorption, there will be a sensitizing effect caused by secondary electrons generated therefrom during exposure. In addition, since the atomic weight of the tin atom is large, the effect of suppressing acid diffusion from the upper resist to the resist underlayer film is high, and high sensitivity can be achieved while maintaining the LWR performance of the upper resist film itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0148] Figure 1 (A) to (F) are explanatory diagrams of an example (3-layer resist process) of the pattern formation method of the present invention.

[0149] Figure 2 (G) to (P) are explanatory diagrams of an example of the tone inversion type pattern formation method of the present invention (SOC pattern inversion in the 3-layer resist process).

[0150] Figure 3 (Q) to (S) are explanatory diagrams of the landfill property evaluation method. DETAILED DESCRIPTION OF THE INVENTION

[0151] ​​​As described above, there is a demand for a metal-containing film-forming composition having excellent film-forming properties and etching resistance for forming an underlying film of a resist, which can transfer a resist pattern to a substrate to be processed with higher accuracy in a fine patterning process using a multilayer resist method, and a metal-containing film-forming compound useful for the composition.

[0152] The inventors of the present invention focused on organotin compounds that are highly anticipated to be active under EUV exposure and conducted repeated in-depth studies. As described above, tin atoms with a large EUV light absorption have the following characteristics: they have a sensitizing effect caused by secondary electrons generated from them during exposure, and can be made highly sensitive while maintaining the LWR performance of the upper resist film itself. On the other hand, as for the organotin compounds that have been studied for the upper resist film, due to the lack of heat resistance, they cause a drastic volume contraction during baking, so it is difficult to form a uniform film or fill the height difference of the substrate to be processed during high-temperature baking. The inventors of the present invention believe that if an organic molecule having a diol structure (including catechol) and a carboxylic acid ester in the molecule is reacted with tin and polymerized, there is a high possibility that a sufficient molecular weight can be maintained even if the bond is broken during baking, sublimates can be suppressed, heat resistance can be improved, and excellent film-forming properties and filling properties can be exhibited. Also, it is considered that at least one tin atom is contained in the repeating unit, so the tin content is high, and by suppressing the organic part in the repeating unit, the tin content can be further increased, and a metal-containing film-forming composition exhibiting excellent etching resistance can be obtained.

[0153] Therefore, the inventors of the present invention further conducted repeated in-depth studies and found that if it is a metal-containing film-forming compound having a repeating unit represented by the above general formula (P-1) to (P-2), it has excellent film-forming properties and can further increase the tin content, so it becomes a metal-containing film-forming compound having excellent etching resistance, and thus the present invention was completed.

[0154] That is, the present invention relates to a metal-containing film-forming compound, characterized in that the compound is a polymer containing any one or both of the repeating units represented by the following general formula (P-1) or (P-2). This compound can be used in a metal-containing film-forming composition that functions as an underlying film material for a resist used in semiconductor manufacturing.

[0155] [Chemical formula 14]

[0156]

[0157] In the foregoing general formulas (P-1) and (P-2), R1 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. W1 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms, and the foregoing hydrocarbon group contains oxygen, nitrogen, or sulfur atoms as heteroatoms, and may also form an ether bond, a carbonyl group, an ester group, an amide group, and may also form a heterocyclic structure with the heteroatoms spaced apart. R2 represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms containing one or more double bonds or triple bonds, a hydroxyl group, an amino group, or a halogen atom, s1 is an integer of 0 to 1, and n1 is an integer of 0 to 1. Also, these elements in the repeating unit may also include a variety of different ones. W2 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms, and the foregoing hydrocarbon group contains oxygen, nitrogen, or sulfur atoms as heteroatoms, and may also form an ether bond, a carbonyl group, an ester group, an amide group, and may also form a heterocyclic structure with the heteroatoms spaced apart. s2 is an integer of 0 to 1. s3 is 1 or 2, and when s3 is 1, R3 is a hydrogen atom or a hydrocarbon group having a hydroxyl group and 1 to 10 carbon atoms, and when s3 is 2, R3 is an oxygen atom, and together with the carbon atom to which it is bonded, forms a carbonyl group. W2 and R3 may also be bonded to each other to form a ring structure. Also, these elements in the repeating unit may also include a variety of different ones.

[0158] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto. In addition, catechol (1,2-benzenediol) is included in diols, and in this specification, a compound having a 1,2-benzenediol structure may sometimes be referred to as catechol, and diols other than that may be simply referred to as "diols".

[0159] <Compound for forming metal-containing film>

[0160] The metal-containing film-forming compound of the present invention is a metal-containing film-forming compound that can be used in a metal-containing film-forming composition, and is characterized in that the foregoing metal-containing film-forming compound is a polymer containing repeating units represented by the following general formulas (P-1) to (P-2). The foregoing compound can be used in a metal-containing film-forming composition that functions as an underlayer film material for a resist used in semiconductor manufacturing.

[0161] [Chemical formula 15]

[0162]

[0163] In the above general formulas (P-1) and (P-2), R1 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms.

[0164] In general formula (P-1), W1 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group (including an aromatic ring group) having 1 to 40 carbon atoms, and the aforementioned hydrocarbon group contains oxygen atoms, nitrogen atoms, and sulfur atoms as heteroatoms, and can also form an ether bond, a carbonyl group, an ester group, an amide group, and can also form a heterocyclic structure with the aforementioned heteroatoms spaced apart. R2 represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms containing one or more double bonds or triple bonds, a hydroxyl group, an amino group, a halogen atom, s1 is an integer of 0 to 1, and n1 is an integer of 0 to 1. Also, these elements in the repeating unit can also include multiple different ones.

[0165] In general formula (P-2), W2 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group (including an aromatic ring group) having 1 to 40 carbon atoms, and the aforementioned hydrocarbon group contains oxygen atoms, nitrogen atoms, and sulfur atoms as heteroatoms, and can also form an ether bond, a carbonyl group, an ester group, an amide group, and can also form a heterocyclic structure with the aforementioned heteroatoms spaced apart. s2 is an integer of 0 to 1. s3 is 1 or 2, and when s3 is 1, R3 is a hydrogen atom or a hydrocarbon group having a hydroxyl group and 1 to 10 carbon atoms, and when s3 is 2, R3 is an oxygen atom, and together with the carbon atom to which it is bonded, it forms a carbonyl group, and W2 and R3 can also be bonded to each other to form a ring structure. Also, these elements in the repeating unit can also include multiple different ones.

[0166] In the above general formulas (P-1) to (P-2), R1 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. From the perspective of raw material availability, it is preferably n-butyl, t-butyl, n-octyl, benzyl, and more preferably n-butyl. Also, considering the ease of radical cleavage of the Sn-alkyl bond, t-butyl and benzyl are also preferred.

[0167] In addition, regarding the alkyl names below, sometimes n is recorded to indicate a primary alkyl group, or s, t, or secondary, tertiary, etc. are respectively recorded to indicate secondary and tertiary alkyl groups.

[0168] In the above general formula (P-1), W1 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group (including aromatic groups) with 1 to 40 carbon atoms, which may or may not be substituted, and the aforementioned hydrocarbon group contains oxygen atoms, nitrogen atoms, and sulfur atoms as heteroatoms, and may also form ether bonds, carbonyl groups, ester groups, amide groups, and may also form a heterocyclic structure by spacing the aforementioned heteroatoms such as spacer amide groups and ester groups. From the viewpoints of heat resistance and increasing the Sn content, W1 is preferably a linear, branched or cyclic saturated or unsaturated hydrocarbon group with 1 to 20 carbon atoms that may also contain hydroxyl groups or amino groups (the aforementioned hydrocarbon group contains oxygen atoms, nitrogen atoms, and sulfur atoms as heteroatoms, and may also form ether bonds, carbonyl groups, ester groups). s1 is an integer from 0 to 1. From the viewpoint of increasing the tin content, s1 is preferably 0. From the viewpoints of thermal fluidity and landfillability, since it is better to contain an organic chain, s1 is preferably 1. In addition, when s1 is 0, it means that the carbonyl group is singly bonded.

[0169] More specifically, W1 is preferably a linear, branched or cyclic saturated or unsaturated hydrocarbon group with 1 to 10 carbon atoms that may also contain hydroxyl groups or amino groups (the aforementioned hydrocarbon group contains oxygen atoms, nitrogen atoms, and sulfur atoms as heteroatoms, and may also form ether bonds, carbonyl groups, ester groups), or any one of the groups represented by the following general formulas (W1-1) to (W1-4).

[0170] [Chemical formula 16]

[0171]

[0172] In the above general formulas (W1-1) to (W1-4), R W is a divalent organic group with 1 to 23 carbon atoms, and #1 and #2 respectively represent the bonding parts to the ester and benzene ring.

[0173] In the above general formula (P-1), R2 is an alkyl group with 1 to 20 carbon atoms that may or may not be substituted, a cycloalkyl group with 3 to 20 carbon atoms that may or may not be substituted, an aliphatic unsaturated hydrocarbon group with 2 to 20 carbon atoms that may or may not be substituted and contains one or more double bonds or triple bonds, a hydroxyl group, an amino group, or a halogen atom. From the viewpoints of thermosetting properties or breaking molecular symmetry, it is preferably a hydroxyl group.

[0174] More specific examples of (P-1) containing W1 can be exemplified by the following formula, but are not limited thereto. In the following formula, R1 and R w represent the same groups as above, and the content in parentheses represents the repeating unit.

[0175] [Chemical formula 17]

[0176]

[0177] In the above general formula (P-2), W2 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group (including aromatic groups) having 1 to 40 carbon atoms with or without substitution, and the aforementioned hydrocarbon group contains an oxygen atom, a nitrogen atom, a sulfur atom, and can also form an ether bond, a carbonyl group, an ester group, an amide group, and can also form a heterocyclic structure by interposing amide groups, ester groups, etc. From the viewpoints of heat resistance and increase in Sn content, W2 is preferably a linear, branched or cyclic saturated or unsaturated hydrocarbon group (including aromatic groups) having 1 to 20 carbon atoms that may also contain a hydroxyl group or an amino group (the aforementioned hydrocarbon contains an oxygen atom, a nitrogen atom, a sulfur atom, and can also form an ether bond, a carbonyl group, an ester group).

[0178] More specifically, W2 is preferably a linear, branched or cyclic saturated or unsaturated hydrocarbon group (including aromatic ring groups) having 1 to 10 carbon atoms that may also contain a hydroxyl group or an amino group, or a cyclic hydrocarbon group formed by bonding with R3 (the aforementioned hydrocarbon group contains an oxygen atom, a nitrogen atom, a sulfur atom, and can also form an ether bond, a carbonyl group, an ester group), or any one of the groups represented by the following general formulas (W2-1) to (W2-4).

[0179] [Chemical formula 18]

[0180]

[0181] In the above general formulas (W2-1) to (W2-4), Rw is a divalent organic group having 1 to 23 carbon atoms, and #1 and #2 respectively represent the bonding parts to the ester group and the carbon atom.

[0182] In the above general formula (P-2), s2 is an integer of 0 to 1, s3 is 1 or 2, and when s3 is 1, R3 is a hydrogen atom or a hydrocarbon group having a hydroxyl group with 1 to 10 carbon atoms, and when s3 is 2, R3 is an oxygen atom, and together with the carbon atom bonded thereto, it forms a carbonyl group. W2 and R3 can also bond to each other to form a ring structure. From the viewpoint of increasing the tin content, S2 is preferably 0, and from the viewpoints of thermal fluidity and landfillability, since it is better to contain an organic chain, S2 is preferably 1. In addition, when s2 is 0, it means a single bond of the carbonyl group.

[0183] Specific examples of (P-2) containing W2 can be listed as the following formula, but are not limited thereto. In the following formula, R1, R w represents the same group as above, and the content in the parentheses represents the repeating unit.

[0184] [Chemical formula 19]

[0185]

[0186] In the above general formulas (W1-1) to (W1-4) and (W2-1) to (W2-4), R W is a divalent organic group having 1 to 23 carbon atoms, R WThe ideal structure can be exemplified by the following structures, but is not limited thereto (* respectively represent the bonding parts with the carbon atoms of the carbonyl group).

[0187] [Chemical formula 20]

[0188]

[0189] In addition, in the aforementioned general formulas (W1-1) to (W1-4) and (W2-1) to (W2-4), R W is preferably an unsaturated hydrocarbon having 2 to 23 carbon atoms.

[0190] If it is a metal-containing film-forming compound having such a structure, the thermosetting property can be further improved.

[0191] Also, in the aforementioned general formulas (W1-1) to (W1-4) and (W2-1) to (W2-4), R W being a structure represented by the following general formula (1) is more ideal from the viewpoints of improving the thermosetting property and the tin content rate.

[0192] [Chemical formula 21]

[0193]

[0194] In the aforementioned general formula (1), R a , R b and R C are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and R a and R b can also be bonded to form a cyclic substituent. *1 and *2 respectively represent the bonding parts with the carbonyl group, but *1 and *2 can also be reversed.

[0195] The carboxylic acid raw material containing the aforementioned general formula (1) can be synthesized by ring-opening a cyclic anhydride. At this time, if an asymmetric cyclic carboxylic anhydride is ring-opened, it will become a mixture of two kinds, so it becomes a bonding form as described above. Due to the existence of such isomers, the crystallinity can be suppressed, and an improvement in the solvent solubility and an improvement in the landfill property due to the improvement in the thermal fluidity can be expected. For example, in the ring-opening reaction of itaconic anhydride derivative shown below and 4-(2-aminoethyl)catechol, the nucleophilic reaction of the amine occurs at the carbonyl group beside the unsaturated methylene (>C=CH2) or at the carbonyl group beside the saturated methylene (>CH2), and the products are different and become a mixture of two isomers.

[0196] [Chemical formula 22]

[0197]

[0198] It is more desirable from the viewpoint of increasing the tin content rate that the terminal structure of the polymer having the repeating units represented by the general formulae (P-1) to (P-2) is represented by the general formulae (T-1) to (T-2).

[0199] [Chemical formula 23]

[0200]

[0201] In the general formulae (T-1) to (T-2) above, R1, R2, R3, W1, W2, s1, s2 and s3 are the same as those in the general formulae (P-1) to (P-2), and their ideal structures are also as described above.

[0202] If the terminal structure of the polymer having the repeating units represented by the general formulae (P-1) to (P-2) is represented by the general formulae (T-1) to (T-2), then both the repeating units and the terminal structure contain tin atoms, so the tin content rate can be increased. Also, the tin-alkyl bond generates free radicals due to heat, so the crosslinking reaction is promoted by these free radicals. Moreover, since the thermosetting property can also be improved, sublimates can be suppressed, and volume shrinkage that causes deterioration of landfill properties can also be expected to be suppressed. Thereby, a metal-containing film-forming compound used for a resist underlayer film material or the like having excellent film-forming properties and etching resistance after high-temperature baking can be provided.

[0203] A polymer containing the repeating units represented by the general formulae (P-1) to (P-2) and having a terminal represented by the general formulae (T-1) to (T-2) can generally be synthesized by performing a condensation reaction (Step 1) using a compound (X) containing both adjacent hydroxyl groups (hydroxyl groups adjacent with a two-carbon atom interval) and a carboxylic acid and an alkyltin trichloride (Y), and then further condensing the obtained condensate with a carboxylic acid (T) having the structure of (T-1) to (T-2) (Step 2). (R, R1, R2, R3, n1, s1, s2, W1, W2 are the same as above. In addition, hereinafter, s3 is set to 1.)

[0204] [Chemical formula 24]

[0205]

[0206] [Chemical formula 25]

[0207]

[0208] Also, the compound of the unit represented by (T) used in the above (Step 2) can be synthesized by successively performing condensation using 1 equivalent of a tin compound such as a dialkyltin dichloride or a dialkyltin oxide (Z') and a compound (X) containing both adjacent hydroxyl groups (hydroxyl groups adjacent with a two-carbon atom interval) and a carboxylic acid (Reaction 1). (R1, R2, R3, n1, s1, s2, W1, W2 are the same as above.)

[0209] General formula for the condensation of dialkyltin oxide (Z’) and catechol derivative (X)

[0210] [Chemical formula 26]

[0211]

[0212] General formula for the condensation of dialkyltin dichloride (Z’) and diol derivative (X) (s3 = 1)

[0213] [Chemical formula 27]

[0214]

[0215] Furthermore, from the perspective of solubility, it is more ideal if the terminal structure of the polymer having the repeating units of the above general formulas (P-1) to (P-2) is *-OC(=O)R (where R is a monovalent organic group, and * represents the bonding part with the Sn atom in the polymer).

[0216] If the terminal structure of the polymer having the repeating units of the above general formulas (P-1) to (P-2) is *-OC(=O)R (where R is a monovalent organic group, and * represents the bonding part with the Sn atom in the polymer), since R can be freely changed, if a bulky structure is incorporated, improvement in solubility can be expected. In addition, a crosslinked structure can be imparted to it. Therefore, sublimates can be more suppressed, and volume shrinkage that causes deterioration in landfillability can also be expected to be suppressed. Thereby, a resist underlayer film material having excellent film-forming properties even after high-temperature baking can be provided.

[0217] A polymer containing the repeating units represented by the above general formulas (P-1) to (P-2) and having a terminal of *-OC(=O)R (where R is a monovalent organic group, and * represents the bonding part with the Sn atom in the polymer) can generally be synthesized by carrying out a condensation reaction (step 1) using a compound (X) containing both adjacent hydroxyl groups (hydroxyl groups adjacent with a two-carbon atom interval) and a carboxylic acid, and an alkyltin trichloride (Y), and then further condensing the obtained condensate with a carboxylic acid (Z) (step 2). (R, R1, R2, R3, n1, s1, s2, W1, W2 are the same as described above.)

[0218] [Chemical formula 28]

[0219]

[0220] [Chemical formula 29]

[0221]

[0222] Furthermore, the usage amount of (X) during the implementation of the above (Step 1) should preferably be 0.6 to 0.95 equivalents relative to (Y), more preferably 0.7 to 0.9 equivalents. Therefore, after the completion of (Step 1), a part of the Sn-Cl bonds that have not been consumed by polymerization remains. Therefore, regarding the usage amounts of (T) and (Z), they should preferably be amounts that can react with this residue part, so they should preferably be 0.15 to 1.2 equivalents, more preferably 0.3 to 0.9 equivalents. For example, if it is considered that 0.9 equivalents of 3,4-dihydroxybenzoic acid as (X) reacts with 1.0 equivalent of alkyltin trichloride as (Y), 0.3 equivalent of the Sn-Cl bonds that have not been consumed by polymerization remains. The residues of these Sn-Cl bonds can be further condensed using the above (Step 2). An example of (Step 2) shows the reaction of the condensate of (Step 1) with methacrylic acid. If the carboxylic acid used in (Step 2) is changed to (T), it will become a polymer with a structure represented by (T-1) to (T-2) at the end.

[0223] [Chemical Formula 30]

[0224]

[0225] Furthermore, the condensation reaction (Step 1) using the above (X) and (Y), and the condensation reaction (Step 2) using the condensate obtained in Step 1 and (T) and (Z) can generally be carried out without a solvent or in a solvent, at room temperature or as required with cooling or heating. Examples of the solvents used include: ethers such as diethyl ether, dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, 1,4-dioxane; chlorinated solvent classes such as dichloromethane, chloroform, dichloroethane, trichloroethylene; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, isobutyl methyl ketone; esters such as ethyl acetate, n-butyl acetate, propylene glycol methyl ether acetate; lactones such as γ-butyrolactone; aprotic polar solvent classes such as dimethyl sulfoxide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, hexamethylphosphoric triamide. They can be used alone or in a mixture of two or more. These solvents can be used in the range of 0 to 3000 parts by mass relative to 100 parts by mass of the reaction raw materials.

[0226] Furthermore, a base catalyst can also be added as a catalyst. As the base catalyst used, inorganic salts such as potassium carbonate and sodium hydroxide can be used, but since it is difficult to remove them, organic bases such as triethylamine, diisopropyl ethylamine, N,N-dimethylaniline, pyridine, 4-dimethylaminopyridine are preferably used. Its usage amount should preferably be 2.5 to 3.5 equivalents relative to stannic trichloride, more preferably 3.0 to 3.2 equivalents. The reaction temperature should preferably be from -50°C to about the boiling point of the solvent, more preferably from room temperature to 130°C.

[0227] The condensation reaction method (Step 1) includes methods such as feeding (X) and (Y) at once, dropping (Y) into (X), or dropping a solution in which (X) or (X) is dissolved in a reaction solvent into (Y). After the condensation reaction in Step 1 is completed, in order to remove unreacted raw materials, catalysts, etc., methods such as raising the temperature of the reaction kettle to 130 - 230 °C and removing volatile components at about 1 - 50 mmHg, or using appropriate poor solvents and good solvents to fractionate impurities and the obtained polymer can also be added. Usually, the reaction of (Step 2) can also be carried out by adding (T) and (Z) to the reaction system after Step 1 is completed. After the condensation reaction in (Step 2) is completed, steps to remove impurities, etc. in the same way as the above purification method can be added.

[0228] If the terminal structure of the polymer having the repeating units of the above general formulas (P-1) to (P-2) is *-OC(=O)R (R is a monovalent organic group, and * represents the bonding part with the Sn atom in the polymer), since R can be freely changed, if a bulky structure is incorporated, improvement in solubility and thermal fluidity can be expected. In addition, a crosslinked structure can also be given to it. Therefore, sublimates can be suppressed, and volume shrinkage that causes deterioration of landfill properties can also be expected. The carboxylic acid raw material containing R, for example, if it is a monofunctional carboxylic acid having a linear substituted or unsubstituted hydrocarbon group such as acetic acid, propionic acid, glycine, etc.; a monofunctional carboxylic acid having a branched substituted or unsubstituted hydrocarbon group such as pivalic acid, 2-aminoisobutyric acid, etc.; a monofunctional carboxylic acid having a cyclic substituted or unsubstituted hydrocarbon group such as cyclopropanecarboxylic acid, 3,3-difluorocyclobutanecarboxylic acid, etc., there is no particular limitation. From the viewpoint of thermosetting properties, a group containing an unsaturated hydrocarbon group, a group containing a hydroxyl group, and a group in which a protecting group detaches due to heat or acid to generate a hydroxyl group or a carboxyl group are more preferable.

[0229] Furthermore, the aforementioned R is preferably any one of the groups represented by the following general formulas (A-1) to (A-4), the following general formula (3), and the following general formula (4).

[0230] [Chemical formula 31]

[0231]

[0232] In the aforementioned general formulas (A-1) to (A-4), Y A1 , Y A2 can be the same or different from each other, and is a substituted or unsubstituted divalent organic group having 1 - 23 carbon atoms and being saturated or having 2 - 23 carbon atoms and being unsaturated (such as an aliphatic hydrocarbon group), a substituted or unsubstituted arylene group having 6 - 30 carbon atoms, or a substituted or unsubstituted arylalkylene group having 7 - 31 carbon atoms. R Ais a hydrogen atom, a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms and being saturated or having 2 to 20 carbon atoms and being unsaturated (such as an aliphatic hydrocarbon group), a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, R A1 is an organic group represented by the following general formula (2) in which a protecting group is removed by the action of either or both of an acid and heat to generate one or more hydroxyl groups or carboxyl groups, and * represents the bonding portion to the carbonyl group.

[0233] [Chemical formula 32]

[0234]

[0235] In the aforementioned general formula (2), R A2 is an organic group in which a protecting group is removed by the action of either or both of an acid and heat, and * represents the bonding portion to Y A1 or Y A2 bonding portion.

[0236] In the above general formulas (A-1) to (A-4), Y A1 , Y A2 may be the same as or different from each other, and is a substituted or unsubstituted divalent organic group having 1 to 23 carbon atoms and being saturated or having 2 to 23 carbon atoms and being unsaturated (preferably a hydrocarbon group), a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkylene group having 7 to 31 carbon atoms. R A is a hydrogen atom, a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms and being saturated or having 2 to 20 carbon atoms and being unsaturated (such as an aliphatic hydrocarbon group), a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, R A1 is an organic group represented by the above general formula (2) in which a protecting group is removed by the action of either or both of an acid and heat to generate one or more hydroxyl groups or carboxyl groups. Considering the thermal fluidity, it is preferably (A-4), and considering the viewpoint of increasing the tin content, it is preferably (A-1).

[0237] In the above general formulas (A-1) to (A-4), Y A2 The ideal structure of can be exemplified as the following structures, but is not limited thereto. In the following formula, * a represents the bonding portion to R A1 , * b represents another bonding portion.

[0238] [Chemical formula 33]

[0239]

[0240] In the above general formula (A-3), R Ais a hydrogen atom, a saturated monovalent organic group with 1 to 20 carbon atoms (such as aliphatic hydrocarbon group) with or without substitution or an unsaturated monovalent organic group with 2 to 20 carbon atoms, an aryl group with 6 to 30 carbon atoms with or without substitution, or an arylalkyl group with 7 to 31 carbon atoms with or without substitution. From the viewpoints of suppressing sublimation and increasing the Sn content, it is preferably a hydrogen atom.

[0241] In the above general formula (2), R A2 is an organic group in which a protecting group (thermoacid-labile group) detaches due to the action of either or both of an acid and heat, and is preferably a tertiary hydrocarbon group or a group that forms an acetal structure together with an adjacent oxygen atom, and is particularly preferably a tertiary hydrocarbon group.

[0242] The aforementioned tertiary hydrocarbon group preferably has 4 to 20 carbon atoms, and is particularly preferably a tert-butyl group from the viewpoints of suppressing sublimation of thermal decomposition products and ease of raw material acquisition. Specific examples are as shown below, but are not limited thereto. In addition, in the following formula, * represents a chemical bond with an oxygen atom.

[0243] [Chemical formula 34]

[0244]

[0245] [Chemical formula 35]

[0246]

[0247] [Chemical formula 36]

[0248]

[0249] [Chemical formula 37]

[0250]

[0251] Specific examples of the aforementioned group that forms an acetal structure are as shown below, but are not limited thereto. In addition, in the following formula, * represents a chemical bond with an oxygen atom.

[0252] [Chemical formula 38]

[0253]

[0254] [Chemical formula 39]

[0255]

[0256] [Chemical formula 40]

[0257]

[0258] If it is such a metal-containing film-forming compound, it will become a metal-containing film-forming compound with excellent solvent solubility and thermal fluidity. Also, R A1In [compound name], since it contains a bulky organic group in its structure where the protecting group detaches due to the action of either or both of acid and heat, when it is used in a metal-containing film-forming composition, they will detach during baking, so the tin content will increase, and it becomes a metal-containing film-forming compound with excellent dry-etching resistance. In addition, due to the presence of terminal OH groups and α-hydrogens in the hydroxyl groups and carboxyl groups generated by the detachment, they are prone to react with the free radicals generated by the cleavage of the tin-carbon bond during baking and cause crosslinking reactions, with excellent thermosetting properties. Therefore, volume shrinkage can be inhibited, and a metal-containing film-forming composition such as an anti-reflective coating material with excellent film-forming properties and filling properties even after high-temperature baking can be provided.

[0259] [Chemical formula 41]

[0260]

[0261] In the above general formula (3), X is a divalent organic group having 1 to 31 carbon atoms, B is the following general formula (B), and * represents the bonding part to the carbonyl group.

[0262] [Chemical formula 42]

[0263] B = *-Y B -R B (B)

[0264] In the above general formula (B), Y B is a saturated divalent organic group having 1 to 20 carbon atoms or an unsaturated divalent organic group having 2 to 20 carbon atoms (such as an aliphatic hydrocarbon group) with or without substitution, a divalent arylene group having 6 to 30 carbon atoms with or without substitution, or a divalent arylalkylene group having 7 to 31 carbon atoms with or without substitution, and R B is a hydroxyl group or any one of the structures represented by the following general formulas (B-1) to (B-3).

[0265] [Chemical formula 43]

[0266]

[0267] In the above general formulas (B-1) to (B-3), R B1 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents the bonding part to Y B 's bonding part.

[0268] In the above general formula (3), X is a divalent organic group having 1 to 31 carbon atoms, B is the above general formula (B), and * represents the bonding part to the carbonyl group. In the above general formula (B), Y Bis a saturated or unsaturated divalent organic group (such as aliphatic hydrocarbon group) with 1 to 20 carbon atoms with or without substitution, a divalent arylene group with 6 to 30 carbon atoms with or without substitution, or a divalent arylalkylene group with 7 to 31 carbon atoms with or without substitution, R B is preferably a hydroxyl group or any one of the structures represented by the above general formulas (B-1) to (B-3). Further, in the above general formulas (B-1) to (B-3), R B1 is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, and from the viewpoint of suppressing sublimation, it is preferably a hydrogen atom.

[0269] Examples of the ideal structure of the above general formula (B) include, but are not limited to, the following structures. In addition, in the following formulas, * represents a bond with a carbonyl group.

[0270] [Chemical formula 44]

[0271]

[0272] If it is such a metal-containing film-forming compound, it will be a metal-containing film-forming compound with excellent solvent solubility and thermal fluidity. Further, since R B contains a hydroxyl group or an unsaturated bond, when it is used in a metal-containing film-forming composition, they will cause a crosslinking reaction during baking, so it has excellent thermosetting properties. In addition, since it reacts with free radicals generated by the cleavage of the tin-carbon bond to promote the crosslinking reaction and has excellent thermosetting properties, volume shrinkage can be suppressed, and a metal-containing film-forming composition with excellent film-forming properties and planarization characteristics / embedding characteristics even after high-temperature baking can be provided.

[0273] [Chemical formula 45]

[0274]

[0275] In the above general formula (4), X is a divalent organic group with 1 to 31 carbon atoms, C is the following general formulas (C-1) to (C-4), and * represents a bonding part with a carbonyl group.

[0276] [Chemical formula 46]

[0277]

[0278] In the above general formulas (C-1) and (C-3), R C1 is a hydrogen atom or a methyl group, and in the same formula, they can be the same or different from each other. In (C-3) to (C-4), R C2is a hydrogen atom, a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms with or without substitution (such as an aliphatic hydrocarbon group), an aryl group having 6 to 30 carbon atoms with or without substitution, or an arylalkyl group having 7 to 31 carbon atoms with or without substitution. * indicates the bonding part to the carbonyl group.

[0279] In the above general formula (4), X is a divalent organic group having 1 to 31 carbon atoms, and specific examples include: a saturated divalent hydrocarbon group having 1 to 23 carbon atoms with or without substitution or an unsaturated divalent hydrocarbon group having 2 to 23 carbon atoms with or without substitution, an arylene group having 6 to 30 carbon atoms with or without substitution, an arylalkylene group having 7 to 31 carbon atoms with or without substitution, etc. C is a group represented by the above general formula (C-1) to (C-4). In (C-1) and (C-3), R C1 From the viewpoint of thermal fluidity, it is preferably a methyl group, and from the viewpoint of curability, it is preferably a hydrogen atom. Also, R in (C-3) and (C-4) C2 From the viewpoint of thermal fluidity, it is preferably a structure described above other than a hydrogen atom.

[0280] In the above general formula (C-1) to (C-4), R C2 The ideal structure can be exemplified as the following structures, but is not limited thereto. In addition, in the following formulas, * indicates the atomic bond to the nitrogen atom.

[0281] [Chemical formula 47]

[0282]

[0283] If it is a metal-containing film-forming compound having such a structure, since it contains an organic group represented by the above general formula (4), it will be a metal-containing film-forming compound with excellent solvent solubility and heat resistance characteristics. In addition, since the terminal contains any one of the structures represented by the above general formula (C-1) to (C-4), the crosslinking group density is high, the drastic volume shrinkage during baking can be reduced, and the thermal fluidity is also good. Therefore, a metal-containing film-forming composition with excellent filling / planarization characteristics can be provided.

[0284] As in (P-1) or (P-2), compounds and polymers containing Sn-C bonds generate free radicals while the Sn-C bonds dissociate, so the hardening reaction proceeds due to the generated free radicals (Formula 1). On the other hand, the promotion of the hardening reaction requires the re-bonding of free radicals with each other, so the hardening takes time or requires high temperature to increase the generation efficiency of free radicals. The polymer of the present invention contains at least one tin atom in the repeating unit. Since it contains Sn-C bonds, many free radicals can be generated within one molecule. Therefore, the generation efficiency of free radicals and the possibility of re-bonding are improved, so the hardenability is excellent. In addition, since it is a polymer, the re-bonding of free radicals with each other is faster than the decomposition of low-molecular substances that will sublime, and the heat resistance is also excellent. Also, as described above, by introducing organic groups having unsaturated groups and hydroxyl groups at the ends and main chains, they not only become acceptors of free radicals, but also the unsaturated groups cause thermal cross-linking with each other and form a film with more excellent hardenability. (Formula 2). As a result, the sublimates caused by thermal decomposition can also be suppressed, and a resist underlayer film material with excellent film-forming properties and filling properties can be provided.

[0285] [Chemical formula 48]

[0286]

[0287] [Chemical formula 49]

[0288]

[0289] Y in the above general formulas (A-1) to (A-4) A1 , the ideal structures of X in the above general formula (3) or X in the above general formula (4) can be exemplified as the following structures, but are not limited thereto. In addition, in the following formulas, * represents the bonding part with the carbon atom of the carbonyl group or represents * in the formulas (A-1) to (A-4), formula (3), and formula (4).

[0290] [Chemical formula 50]

[0291]

[0292] Preferably, Y in the above general formulas (A-1) to (A-4) A1 , X in the above general formula (3), or X in the above general formula (4) is a metal-containing film-forming compound having an unsaturated hydrocarbon group with 2 to 23 carbon atoms.

[0293] Y in the above general formulas (A-1) to (A-4) A1 , X in the above general formula (3), or X in the above general formula (4) is an unsaturated hydrocarbon group with 2 to 23 carbon atoms, then the thermosetting property of the above metal-containing film-forming compound can be further improved.

[0294] Also, Y in the above general formulas (A-1) to (A-4) can be providedA1 、X in the above general formula (3) or X in the above general formula (4) is a metal-containing film-forming compound of the following general formula (1).

[0295] [Chemical formula 51]

[0296]

[0297] In the above general formula (1), R a 、R b and R c are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and R a and R b may also be bonded to form a cyclic substituent. *1 and *2 respectively represent the bonding parts to the carbonyl group, and *1 and *2 may also be inverted.

[0298] The carboxylic acid raw material containing the above general formula (1) can be synthesized by ring-opening the acid anhydride. At this time, if the asymmetric carboxylic anhydride is ring-opened, it will become a mixture of two kinds, so it becomes the bonding form as described above. By the existence of such isomers, crystallinity can be suppressed, and improvement in solvent solubility and improvement in flatness characteristics due to improvement in thermal fluidity can be expected.

[0299] [Chemical formula 52]

[0300]

[0301] In the above general formula (1), R a 、R b and R c are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and R a and R b may also be bonded to form a cyclic substituent. From the viewpoint of suppressing sublimates, a hydrogen atom is particularly preferred.

[0302] The ratio Mw / Mn (that is, the dispersity) of the weight-average molecular weight Mw and the number-average molecular weight Mn in terms of polystyrene of the metal-containing film-forming compound by the gel permeation chromatography (GPC) method using tetrahydrofuran should preferably exceed 1.50, and more preferably be 1.80 or more. By definition, if it is a single-molecule compound, Mw / Mn is 1.00, but due to the separation property of GPC, there are sometimes cases where the measured value exceeds 1.00. Generally speaking, for a polymer having a repeating unit, it is extremely difficult to approach Mw / Mn = 1.00 without using a special polymerization method, and it becomes a distribution having Mw and a value where Mw / Mn exceeds 1. In the present invention, in order to distinguish a single-molecule compound and a polymer, as an index indicating a polymer, Mw / Mn>1.50 is defined. In addition, the above index can also be applied to a mixture of two or more kinds of metal-containing film-forming compounds.

[0303] <Composition for forming metal-containing film>

[0304] Furthermore, the present invention can provide a composition for forming a metal-containing film, which functions as an underlayer film material for a resist used in semiconductor manufacturing. The composition for forming a metal-containing film is characterized by containing:

[0305] (a) The metal-containing film-forming compound of the present invention as described above, and

[0306] (b) An organic solvent.

[0307] In such a composition for forming a metal-containing film, since it contains an organotin compound having excellent heat resistance and thermal fluidity, a metal-containing film such as an underlayer film for a resist can be formed, which has excellent dry etching resistance against known organic underlayer film materials and at the same time has a high degree of filling / planarization characteristics.

[0308] Hereinafter, the components contained in the composition for forming a metal-containing film of the present invention other than the above (a) metal-containing film-forming compound will be described.

[0309] <(b) Organic solvent>

[0310] The (b) organic solvent that can be used in the composition for forming a metal-containing film of the present invention is not particularly limited as long as it can dissolve or disperse the above (a) metal-containing film-forming compound, (c) crosslinking agent, (d) surfactant, (e) fluidity promoter, (f) acid generator, other additives, etc.

[0311] Specifically, the organic solvents described in paragraphs

[0091] to

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

[0312] (High-boiling solvent)

[0313] In the above composition for forming an underlayer film for a resist, a mixture of one or more organic solvents having a boiling point (value at 1 atmospheric pressure (1013 hPa)) of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher (high-boiling solvents) can also be used as the aforementioned (b) organic solvent.

[0314] If the high-boiling solvent can dissolve or disperse each component in the metal-containing film-forming composition of the present invention, there are no particular restrictions on hydrocarbons, alcohols, ketones, esters, ethers, chlorinated solvents, etc. Specific examples can be exemplified as follows: 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerol, n-nonyl acetate, monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol n-butyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monon-propyl ether, dipropylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monon-propyl ether, tripropylene glycol monobutyl 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, glyceryl triacetate, propylene glycol diacetate, dipropylene glycol methyl n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butanediol diacetate, 1,6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, dibutyl adipate, etc. They can be used alone or in combination.

[0315] If the high-boiling solvent is appropriately selected from the above-mentioned ones in consideration of the temperature for heat-treating the above-mentioned resist underlayer film-forming composition, etc. The boiling point of the high-boiling solvent is preferably 180°C to 300°C, more preferably 200°C to 300°C. It is considered that if the boiling point is such, there is no concern that the volatilization during baking (heat treatment) becomes too fast, so sufficient thermal fluidity can be obtained during film formation, and a resist underlayer film with excellent filling / planarization characteristics can be formed. Also, if the boiling point is such, there is no situation where it remains unvolatile after baking and remains in the film, so there is no concern about adversely affecting the film physical properties such as etching resistance.

[0316] The blending amount of the organic solvent is preferably 200 to 10,000 parts, more preferably in the range of 250 to 5,000 parts, relative to 100 parts by mass of the (a) metal-containing film-forming compound.

[0317] Furthermore, the blending amount when using a high-boiling solvent is preferably 1 to 30 parts by mass with respect to 100 parts by mass of an organic solvent having a boiling point of less than 180°C. With such a blending amount, sufficient thermal fluidity can be imparted during baking, and it will not remain in the film and is not related to the deterioration of film physical properties such as etching resistance, so it is more ideal.

[0318] <Composition for forming an underlayer film of a resist>

[0319] The above composition is a metal-containing film-forming composition that can be used as an underlayer film of a resist used in a multilayer resist method, and can be made into a composition for forming an underlayer film of a resist that further contains one or more of (c) a crosslinking agent, (d) a surfactant, (e) a fluidity promoter, and (f) an acid generator.

[0320] Hereinafter, the above-mentioned components contained in the (a) metal-containing film-forming compound and the underlayer film-forming composition of the resist other than the (b) organic solvent will be described.

[0321] [(c) Crosslinking agent]

[0322] In the above composition for forming an underlayer film of a resist, in order to improve the denseness of the film and further suppress the mutual mixing with the upper layer resist film, (c) a crosslinking agent may be further contained. The crosslinking agent is not particularly limited, and various known crosslinking agents of various systems can be widely used. Examples thereof include: melamine-based crosslinking agents, acrylate-based crosslinking agents, glycoluril-based crosslinking agents, benzoguanamine-based crosslinking agents, urea-based crosslinking agents, β-hydroxyalkylamide-based crosslinking agents, isocyanurate-based crosslinking agents, aziridine-based crosslinking agents, oxazoline-based crosslinking agents, phenol-based crosslinking agents (for example, hydroxymethyl or alkoxymethyl type crosslinking agents of polynuclear phenols), epoxy-based crosslinking agents, and oxetane-based crosslinking agents. The content of the aforementioned (c) crosslinking agent is preferably 5 to 50 parts by mass with respect to 100 parts by mass of the aforementioned (a) metal-containing film-forming compound, and more preferably 10 to 40 parts by mass.

[0323] Specific examples of melamine-based crosslinking agents include: hexamethoxymethylated melamine, hexabutoxymethylated melamine, their alkoxy and / or hydroxy substituents, and their partial self-condensates.

[0324] Specific examples of acrylate-based crosslinking agents include: dipentaerythritol hexaacrylate.

[0325] Specific examples of glycoluril-based crosslinking agents include: tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril, their alkoxy and / or hydroxy substituents, and their partial self-condensates.

[0326] Specific examples of the benzoguanamine-based crosslinking agents include: tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, their alkoxy and / or hydroxy substituents, and their partial self-condensates.

[0327] Specific examples of the urea-based crosslinking agents include: dimethoxymethylated dimethoxyethyleneurea, their alkoxy and / or hydroxy substituents, and their partial self-condensates.

[0328] Specific examples of the β-hydroxyalkylamide-based crosslinking agents include: N,N,N’,N’-tetrakis(2-hydroxyethyl)adipamide.

[0329] Specific examples of the isocyanurate-based crosslinking agents include: triglycidyl isocyanurate, triallyl isocyanurate.

[0330] Specific examples of the aziridine-based crosslinking agents include: 4,4’-bis(ethyleneiminocarbonylamino)diphenylmethane, 2,2-bis(hydroxymethyl)butanol-tris[3-(1-aziridinyl)propionate].

[0331] Specific examples of the oxazoline-based crosslinking agents include: 2,2’-isopropylidenebis(4-benzyl-2-oxazoline), 2,2’-isopropylidenebis(4-phenyl-2-oxazoline), 2,2’-isopropylidenebis(4-phenyl-2-oxazoline), 2,2’-methylenebis-4,5-diphenyl-2-oxazoline, 2,2’-methylenebis-4-phenyl-2-oxazoline, 2,2’-methylenebis-4-tert-butyl-2-oxazoline, 2,2’-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylenebis(2-oxazoline), 2-isopropenyl oxazoline copolymer.

[0332] Specific examples of the polynuclear phenol-based crosslinking agents include the compounds represented by the following general formula (XL-1).

[0333] [Chemical formula 53]

[0334]

[0335] In the formula, S is a single bond or an s-valent hydrocarbon group having 1 to 20 carbon atoms. R4 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. s is an integer of 1 to 5.

[0336] S is a single bond or an s-valent hydrocarbon group having 1 to 20 carbon atoms. s is an integer of 1 to 5, and 2 or 3 is more preferable. Specifically, S can be exemplified by a group obtained by removing s hydrogen atoms from methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylisopropylbenzene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, and eicosane. R4 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Specific examples of the alkyl group having 1 to 20 carbon atoms include: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, octyl, ethylhexyl, decyl, and eicosyl, and it is preferably a hydrogen atom or a methyl group.

[0337] Examples of the compound represented by the above general formula (XL-1) can be specifically exemplified by the following compounds. Among them, from the viewpoints of improving the hardening property and film thickness uniformity of the organic film, it is preferably a hexamethoxymethylated product of triphenylmethane, triphenylethane, 1,1,1-tris(4-hydroxyphenyl)ethane, and tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene. R4 is the same as described above.

[0338] [Chemical formula 54]

[0339]

[0340] [Chemical formula 55]

[0341]

[0342] Epoxy crosslinking agents and oxetane crosslinking agents can be monomeric or polymeric. Specific examples of the monomeric type can be those shown below, but are not limited thereto.

[0343] [Chemical formula 56]

[0344]

[0345] The above compounds can be purchased items, and epoxy crosslinking agents and oxetane crosslinking agents can also be obtained by reacting hydroxyl groups with epibromohydrin, 3-bromomethyloxetane, etc. as shown in the following formula. In the following formula, R5 is a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms that is saturated or having 2 to 20 carbon atoms that is unsaturated, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. Also, not all of the hydroxyl groups need to react and some can remain. In this case, it is preferably that the number of epoxides + oxetanes > the number of hydroxyl groups, and more preferably that the number of epoxides + oxetanes > 2 × the number of hydroxyl groups. Also, the content of these compounds is preferably 5 to 50 parts by mass, and more preferably 10 to 40 parts by mass, relative to 100 parts by mass of the metal-containing film-forming compound described in (a) above.

[0346] [Chemical formula 57]

[0347]

[0348] Specific examples of the compound having a hydroxyl group that can be utilized in the above reaction are listed below, but are not limited thereto.

[0349] [Chemical formula 58]

[0350]

[0351] Furthermore, specific examples of the polymer type include polymers in which the molar fraction of the repeating units represented by the following general formulas (XL-2) and (XL-3) is 20% or more. When the total molar fraction of the structural units represented by the general formulas (XL-2) and (XL-3) is less than 100%, as other structural units, those derived from other acrylates, other methacrylates, other acrylamides, other methacrylamides, crotonates, maleates, itaconates, etc., α,β-unsaturated carboxylic acid esters; α,β-unsaturated carboxylic acids such as methacrylic acid, acrylic acid, maleic acid, itaconic acid; acrylonitrile; methacrylonitrile; α,β-unsaturated lactones such as 5,5-dimethyl-3-methylene-2-oxotetrahydrofuran; norbornene derivatives, cyclooctene derivatives such as 2,5 .1 7,10 dodecene derivatives and other cyclic olefins; α,β-unsaturated carboxylic anhydrides such as maleic anhydride and itaconic anhydride; allyl ethers; vinyl ethers; vinyl esters; any structural unit of vinyl silanes. Further, the weight-average molecular weight of their polymers is preferably 1,000 to 20,000, and the GPC dispersity (Mw / Mn) is preferably 2.0 or less. Further, the content of these compounds is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, relative to 100 parts by mass of the metal-containing film-forming compound (a) described above. In addition, the weight-average molecular weight (Mw), number-average molecular weight (Mn) in terms of polystyrene converted by GPC using tetrahydrofuran as an eluent are determined, and then the dispersity (Mw / Mn) is calculated.

[0352] [Chemical formula 59]

[0353]

[0354] In the formula, R6 is a hydrogen atom or a methyl group, R7 is a hydrogen atom or a group selected from the following formulas (2-1) to (2-3), and L1 represents a single bond, a divalent organic group containing -C(=O)O- or -C(=O)NH- or -C(=O)NCH3-.

[0355] From the viewpoint of curing properties, R7 in the above general formula (XL-2) is preferably such that the number of the radicals of (2-1) to (2-3) > the number of hydrogen atoms, and more preferably the number of the radicals of (2-1) to (2-3) > 2 × the number of hydrogen atoms.

[0356] [Chemical Formula 60]

[0357]

[0358] In the formula, R6 is a hydrogen atom or a methyl group, and R8 is a group selected from the following formulas (2-1) to (2-3).

[0359]

[0360] In the above formula, the dashed line represents an atomic bond.

[0361] <(d) Surfactant>

[0362] In the above composition for forming an underlayer film of a resist, in order to improve coatability during spin coating, (d) a surfactant can be added. As the surfactant, those described in

[0142] to

[0147] of Japanese Patent Laid-Open No. 2009-269953 can be used, for example. When adding the surfactant, the addition amount is preferably 0.01 to 10 parts, more preferably 0.05 to 5 parts, relative to 100 parts by mass of the above (a) metal-containing film-forming compound.

[0363] <(e) Fluidity Promoter>

[0364] Furthermore, the above composition for forming an underlayer film of a resist may further be blended with other compounds or polymers. The fluidity promoter has the effect of mixing with the metal-containing film-forming compound of the present invention and improving the film-forming property during spin coating and the filling property on a substrate having height differences. Also, the fluidity promoter is preferably a material having a high carbon atom density and high etching resistance.

[0365] Such materials may include: phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,4-xylenol, 2,6-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, 2-phenylphenol, 3-phenylphenol, 4-phenylphenol, 3,5-diphenylphenol, 2-naphthol, 3-naphthol, 4-naphthol, 4-tritylphenol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, catechol, 4-tert-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2-methoxy-5-methylphenol, 2-tert-butyl-5-methylphenol, pyrogallol, thymol, isothymol, 4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-dimethyl-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-diallyl-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-difluoro-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-diphenyl-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-dimethoxy-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 3,3,3',3',4,4'-hexamethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 2,3,2',3'-tetrahydro-(1,1')-spirobiindene-5,5'-diol, 5,5'-dimethyl-3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol, 7-methoxy-2-naphthol, and dihydroxynaphthalenes such as 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, methyl 3-hydroxynaphthalene-2-carboxylate, indene, hydroxyindene, benzofuran, hydroxyanthracene, acenaphthene, biphenyl, bisphenol, triphenol, dicyclopentadiene, indane, 4-vinylcyclohexene, norbornadiene, 5-vinylnorborn-2-ene, α-pinene, β-pinene, limonene, etc., phenolic resins, polyhydroxystyrene, polystyrene, polyvinylnaphthalene, polyvinylanthracene, polyvinylcarbazole, polyindene, polyacenaphthene, polynorbornene, polycyclodecene, polytetracyclododecene, polytricyclodecene, poly(meth)acrylate and their copolymers.Further, it is also possible to blend a naphthol dicyclopentadiene copolymer described in Japanese Patent Application Laid-Open No. 2004-205685, a bisphenol fluorene novolak resin described in Japanese Patent Application Laid-Open No. 2005-128509, an acenaphthene copolymer described in Japanese Patent Application Laid-Open No. 2005-250434, a fullerene having a phenolic group described in Japanese Patent Application Laid-Open No. 2006-227391, a bisphenol compound and its novolak resin described in Japanese Patent Application Laid-Open No. 2006-293298, a novolak resin of an adamantane phenolic compound described in Japanese Patent Application Laid-Open No. 2006-285095, a bisnaphthol compound and its novolak resin described in Japanese Patent Application Laid-Open No. 2010-122656, a fluorene compound described in Japanese Patent Application Laid-Open No. 2017-119671, a fullerene resin compound described in Japanese Patent Application Laid-Open No. 2008-158002, and the like. The blending amount of the above-mentioned fluidity promoter is preferably 0.001 to 100 parts by mass, more preferably 0.01 to 50 parts by mass, relative to 100 parts by mass of the metal-containing film-forming compound of the present invention.

[0366] Further, in the above-mentioned resist underlayer film-forming composition, a liquid additive having a polyethylene glycol or polypropylene glycol structure, or a thermal decomposable polymer having a weight reduction rate of 40% by mass or more between 30°C and 250°C and a weight average molecular weight of 300 to 200,000 can be preferably used as an additive for imparting filling / planarization characteristics. The thermal decomposable polymer preferably contains a repeating unit having an acetal structure represented by the following general formula (DP1) or (DP1a).

[0367] [Chemical formula 62]

[0368]

[0369] In the formula, R 10 is a hydrogen atom or a saturated or unsaturated monovalent organic group having 1 to 30 carbon atoms which may be substituted. Y is a saturated or unsaturated divalent organic group having 2 to 30 carbon atoms.

[0370] [Chemical formula 63]

[0371]

[0372] In the formula, R 10a is an alkyl group having 1 to 4 carbon atoms. Y a is a saturated or unsaturated divalent hydrocarbon group having 4 to 10 carbon atoms and may also have an ether bond. n represents the average number of repeating units and is 3 to 500.

[0373] <(f) Acid generator>

[0374] In the above composition for forming an underlayer film of a resist, in order to further promote the detachment reaction, an (f) acid generator may be added. The (f) acid generator includes those that generate acid by thermal decomposition and those that generate acid by irradiation, and either one of them may be added. Specifically, the materials described in paragraphs

[0061] to

[0085] of Japanese Patent Laid-Open No. 2007-199653 may be added, but it is not limited thereto.

[0375] The above acid generator may be used alone or in combination of two or more. When adding the acid generator, the addition amount is preferably 0.05 to 50 parts, more preferably 0.1 to 10 parts, relative to 100 parts by mass of the above (a) metal-containing film-forming compound.

[0376] <Method for forming an underlayer film of a resist>

[0377] The present invention provides a method for using the above metal-containing film-forming composition to form an underlayer film of a multilayer resist film that can be used for lithography or a filling film that functions as a planarization film for semiconductor manufacturing.

[0378] In the method for forming an underlayer film of a resist using the metal-containing film-forming composition of the present invention, the above metal-containing film-forming composition is coated on a substrate to be processed by a spin coating method or the like. By using a spin coating method or the like, good filling characteristics can be obtained. After spin coating, baking (heat treatment) is performed to evaporate the solvent, prevent mixing with the upper layer resist film or the intermediate resist film, and promote the crosslinking reaction. The baking is preferably performed in the range of 100°C or higher and 600°C or lower, for 10 to 600 seconds, and more preferably in the range of 200°C or higher and 500°C or lower, for 10 to 300 seconds. Considering the influence on device damage and wafer deformation, the upper limit of the heating temperature in the wafer process for lithography is preferably set to 600°C or lower, and more preferably 500°C or lower.

[0379] Further, in the method for forming an underlayer film of a resist using the metal-containing film-forming composition of the present invention, by coating the metal-containing film-forming composition of the present invention on a substrate to be processed by the same spin coating method or the like, and calcining the metal-containing film-forming composition in an environment with an oxygen concentration of 0.1% by volume or higher and 21% by volume or lower to harden it, a metal-containing film can also be formed.

[0380] By calcining the metal-containing film-forming composition of the present invention in such an oxygen environment, a sufficiently hardened film can be obtained. The environment during baking may be in air, but it is more desirable to enclose inert gases such as N2, Ar, He, etc. in advance to reduce oxygen in order to prevent oxidation of the metal-containing film. In order to prevent oxidation, the oxygen concentration must be controlled, preferably 1000 ppm or less, and more preferably 100 ppm or less (volume basis). Preventing oxidation of the metal-containing film during baking is ideal because there will be no increase in absorption, reduction in etching resistance, etc.

[0381] <Pattern formation method using a resist underlayer film-forming composition>

[0382] Furthermore, the present invention provides a pattern formation method for a two-layer resist process using the above-mentioned metal-containing film-forming composition, characterized in that: a metal-containing film is formed on a substrate to be processed using the above-mentioned metal-containing film-forming composition, a resist upper layer film is formed on the metal-containing film using a photoresist material, after the resist upper layer film is pattern-exposed, it is developed with a developer to form a pattern on the resist upper layer film, using the patterned resist upper layer film as a mask, the pattern is transferred to the metal-containing film by dry etching, and using the patterned metal-containing film as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed.

[0383] The resist upper layer film of the above two-layer resist process exhibits etching resistance to chlorine-based gases. Therefore, in the above two-layer resist process, dry etching of the metal-containing film using the resist upper layer film as a mask should be carried out using an etching gas mainly composed of chlorine-based gas.

[0384] Furthermore, the present invention provides a pattern formation method for a three-layer resist process using such a metal-containing film-forming composition, characterized in that: a metal-containing film is formed on a substrate to be processed using the above-mentioned metal-containing film-forming composition, a resist intermediate film (silicon-containing resist intermediate film) is formed on the metal-containing film using a resist intermediate film material such as a silicon-containing resist intermediate film, a resist upper layer film is formed on the resist intermediate film using a photoresist material, after the resist upper layer film is pattern-exposed, it is developed with a developer to form a pattern on the resist upper layer film, using the patterned resist upper layer film as a mask, the pattern is transferred to the resist intermediate film by dry etching, using the resist intermediate film with the transferred pattern as a mask, the pattern is transferred to the metal-containing film by dry etching, and using the patterned metal-containing film as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed. Hereinafter, an example of using a silicon-containing resist intermediate film as the resist intermediate film will be described.

[0385] In an example of a three-layer resist process, Figure 1 a specific example is illustrated as follows. In the case of a three-layer resist process, as Figure 1 shown in (A) of FIG. 1, after forming a metal-containing film (metal-containing resist underlayer film) 3 on a processed layer 2 laminated on a 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.

[0386] Then, as Figure 1 shown in (B) of FIG. 1, an exposed portion (exposed portion) 6 of the resist upper layer film 5 is exposed, and PEB and development are performed to form a resist upper layer film pattern 5a ( Figure 1 shown in (C) of FIG. 1). Using the obtained resist upper layer film pattern 5a as a mask, the silicon-containing resist intermediate film 4 is etched using a CF-based gas to form a silicon-containing resist intermediate film pattern 4a ( Figure 1 shown in (D) of FIG. 1). After removing the resist upper layer film pattern 5a, the metal-containing film 3 is etched with chlorine plasma using the obtained silicon-containing resist intermediate film pattern 4a as a mask to form a metal-containing film pattern (metal-containing resist underlayer film pattern) 3a ( Figure 1 shown in (E) of FIG. 1). After removing the silicon-containing resist intermediate film pattern 4a, the processed layer 2 is etched using the metal-containing film pattern 3a as a mask, and a pattern 2a is formed on the processed layer ( Figure 1 shown in (F) of FIG. 1).

[0387] Since the silicon-containing resist intermediate film in the above three-layer resist process exhibits etching resistance to chlorine-based gases and hydrogen-based gases, in the above three-layer resist process, dry etching of the metal-containing film using the silicon-containing resist intermediate film as a mask should be performed using an etching gas mainly composed of a chlorine-based gas or a hydrogen-based gas.

[0388] The silicon-containing resist intermediate film in the above three-layer resist process can also ideally use a polysiloxane-based intermediate film. By making the silicon-containing resist intermediate film have an antireflection effect, reflection can be suppressed. Especially for 193 nm exposure, if a material containing a large amount of aromatic groups and having a high etching selectivity to the substrate is used as the organic film, the k value will increase and the substrate reflection will increase. By making it have an absorption that becomes an appropriate k value for the silicon-containing resist intermediate film, reflection can be suppressed, and the substrate reflection can be adjusted to 0.5% or less. As the silicon-containing resist intermediate film having an antireflection effect, for 248 nm and 157 nm exposure, a polysiloxane having a pendant anthracene light-absorbing group and crosslinked by an acid or heat can be ideally used. For 193 nm exposure, a polysiloxane having a pendant phenyl or silicon-silicon bond light-absorbing group and crosslinked by an acid or heat can be ideally used.

[0389] In addition, in terms of a pattern formation method for a four-layer resist process using such a metal-containing film-forming composition, the present invention provides a pattern formation method, which is 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 resist intermediate film on the underlying resist film using a silicon-containing resist intermediate film material, forming an organic anti-reflective coating (BARC) or a conformal film on the silicon-containing resist intermediate film, forming an upper resist film using a photoresist material on the BARC, performing pattern exposure on the upper resist film, developing with a developer, and forming a pattern on the upper resist film, using the patterned upper resist film as a mask, transferring the pattern to the BARC or conformal film and the silicon-containing resist intermediate film by dry etching, using the silicon-containing resist intermediate film with the transferred pattern as a mask, transferring the pattern to the metal-containing film by dry etching, and using the patterned metal-containing film as a mask to process the substrate to be processed to form a pattern on the substrate to be processed.

[0390] Further, the silicon-containing underlying resist film can be replaced with an inorganic hard mask. In this case, at least a metal-containing film is formed on the object to be processed using the metal-containing film-forming composition of the present invention, an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the metal-containing film, a photoresist composition is used to form an upper resist film on the inorganic hard mask, a circuit pattern is formed on the upper resist film, the inorganic hard mask is etched using the patterned upper resist film as a mask, the metal-containing film is etched using the patterned inorganic hard mask as a mask, and then the object to be processed is etched using the patterned metal-containing film as a mask to form a pattern on the object to be processed, whereby a semiconductor device circuit pattern can be formed on the substrate.

[0391] As described above, when forming an inorganic hard mask on a metal-containing film, a silicon oxide film, a silicon nitride film, and a silicon oxynitride film (SiON film) can be formed by a CVD method, an ALD method, etc. For example, regarding the formation method of a silicon nitride film, it is described in Japanese Patent Laid-Open No. 2002-334869 and International Publication No. 2004 / 066377. The film thickness of the inorganic hard mask is preferably 5 to 200 nm, more preferably 10 to 100 nm. Further, the inorganic hard mask can preferably use a SiON film having a high anti-reflection effect. Since the substrate temperature when forming the SiON film reaches 300 to 500 °C, the metal-containing film needs to withstand a temperature of 300 to 500 °C. The metal-containing film-forming composition used in the present invention has high heat resistance and can withstand a high temperature of 300 °C to 500 °C, so an inorganic hard mask formed by a CVD method or an ALD method and a metal-containing film formed by a spin coating method can be combined.

[0392] As described above, a photoresist film may be formed on the inorganic hard mask as the upper resist film, or an organic anti-reflection film (BARC) or a planarization film may be formed on the inorganic hard mask by spin coating, and a photoresist film may be formed thereon. In particular, when a SiON film is used as the inorganic hard mask, a two-layer anti-reflection film of the SiON film and the BARC can suppress reflection even in immersion exposure with a high NA exceeding 1.0. As another advantage of forming the BARC, there is an effect of reducing the tailing of the photoresist pattern immediately above the SiON film.

[0393] In addition, regarding the pattern formation method for a multilayer resist process using such a metal-containing film-forming composition, a lower resist film is formed on the substrate to be processed, the metal-containing film-forming composition of the present invention is coated on the lower resist, and then heat treatment is performed to form a metal-containing film. A photoresist material is used to form an upper resist film on the metal-containing film. After the upper resist film is pattern-exposed, it is developed with a developer to form a pattern in the upper resist film. Using the patterned upper resist film as a mask, the pattern is transferred to the metal-containing film by dry etching. Using the metal-containing film with the transferred pattern as a mask, the pattern is transferred to the lower resist film by dry etching. Then, using the patterned lower resist film as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed, whereby a semiconductor device circuit pattern can be formed on the substrate.

[0394] As described above, a photoresist film may be formed on the metal-containing film as the upper resist film, or an organic planarization film may be formed on the metal-containing film by spin coating, and a photoresist film may be formed thereon. At this time, the pattern can be transferred to the aforementioned organic planarization film and the aforementioned metal-containing film by dry etching.

[0395] As described above, when forming the lower resist film on the substrate to be processed, it can be a method using a coating-type organic lower film material, or a method of forming the lower resist film by CVD method, ALD method, etc. Examples of the coating-type organic lower film material include resins and compositions disclosed in JP-A-2012-001687, JP-A-2012-077295, JP-A-2004-264710, JP-A-2005-043471, JP-A-2005-250434, JP-A-2007-293294, JP-A-2008-065303, JP-A-2004-205685, JP-A-2007-171895, JP-A-2009-014816, JP-A-2007-199653, JP-A-2008-274250, JP-A-2010-122656, JP-A-2012-214720, JP-A-2014-029435, WO2012 / 077640, WO2010 / 147155, WO2012 / 077640, WO2010 / 147155, WO2012 / 176767, JP-A-2005-128509, JP-A-2006-259249, JP-A-2006-259482, JP-A-2006-293298, JP-A-2007-316282, JP-A-2012-145897, JP-A-2017-119671, JP-A-2019-044022, etc.

[0396] In the above multi-layer resist process, the upper resist film can be either positive or negative, and the same one as the commonly used photoresist composition can be used. After spin-coating the photoresist composition, pre-baking is carried out, preferably in the range of 60 to 180 °C for 10 to 300 seconds. Thereafter, exposure is carried out according to the common method, and then baking (PEB) and development are carried out after exposure to obtain a resist pattern. In addition, the thickness of the upper resist film is not particularly limited, preferably 30 to 500 nm, and particularly preferably 50 to 400 nm.

[0397] Furthermore, the exposure light can include high-energy rays with a wavelength of 300 nm or less, specifically, excimer lasers of 248 nm, 193 nm, 157 nm, soft X-rays of 3 to 20 nm, electron beams, X-rays, etc.

[0398] The method for forming the pattern of the upper resist film is preferably pattern formation by optical lithography with a wavelength of 5 nm or more and 300 nm or less, electron beam direct writing, nanoimprinting, or a combination thereof.

[0399] Also, the development method in the aforementioned pattern formation method is preferably development by alkali development or an organic solvent.

[0400] Then, etching is performed using the obtained resist pattern as a mask. For the etching of the silicon-containing resist intermediate film or the inorganic hard mask in the three-layer resist process, a gas based on freon is used and the upper resist pattern is used as a mask. Thereby, a silicon-containing resist intermediate film pattern or an inorganic hard mask pattern is formed.

[0401] Then, using the obtained silicon-containing resist intermediate film pattern or inorganic hard mask pattern as a mask, etching of the metal-containing film is performed. The etching of the metal-containing film is preferably performed using an etching gas mainly composed of a chlorine-based gas.

[0402] The etching of the workpiece to be processed next can also be performed using a conventional method. For example, if the workpiece to be processed is SiO2, SiN, or a silicon dioxide-based low dielectric constant insulating film, etching is performed using a gas based on freon as the main body. When the substrate is etched with a gas based on freon in the three-layer resist process, the silicon-containing resist intermediate film pattern in the three-layer resist process is peeled off simultaneously with the substrate processing.

[0403] The metal-containing film obtained using the composition for forming a metal-containing film of the present invention has excellent etching resistance during the etching of these workpieces to be processed.

[0404] In addition, the workpiece to be processed (substrate to be processed) is not particularly limited, and substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, Al, etc., or those having a processed layer formed thereon can be used. As the processed layer, various Low-k films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si, and their barrier films can be used, and a thickness of 50 to 10,000 nm can generally be formed, and particularly a thickness of 100 to 5,000 nm can be formed. In addition, when forming the processed layer, different materials can be used for the substrate and the processed layer.

[0405] In the pattern formation method using the metal-containing film-forming composition of the present invention, a substrate to be processed having a structure or height difference with a height of 30 nm or more is preferably used. As described above, since the metal-containing film-forming composition of the present invention has excellent filling / planarization characteristics, even if the substrate to be processed has a structure or height difference (concavity and convexity) with a height of 30 nm or more, a flat hardened film can still be formed. The height of the structure or height difference of the substrate to be processed is preferably 30 nm or more, more preferably 50 nm or more, and even more preferably 100 nm or more. In the method of processing a substrate with a height difference of a pattern having the above height, by forming the metal-containing film-forming composition of the present invention into a film and performing filling / planarization, the film thicknesses of the resist intermediate film and the resist upper layer film formed thereafter can be made uniform, so it is easy to ensure the exposure depth tolerance (DOF) during optical lithography and it is very ideal.

[0406] <Tone inversion type pattern formation method using a metal-containing film-forming composition>

[0407] Furthermore, with respect to the tone inversion type pattern formation method using such a metal-containing film-forming composition, the present invention provides a tone inversion type pattern formation method, which is characterized by having the following steps: forming a resist lower layer film on a substrate to be processed, forming a resist intermediate film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film and an organic thin film on the resist lower layer film, using a photoresist material to form a resist upper layer film on the resist intermediate film, or the combination of the inorganic hard mask intermediate film and the organic thin film, performing pattern exposure on the resist upper layer film, developing with a developer, and forming a pattern on the resist upper layer film, using the patterned resist upper layer film as a mask, transferring the pattern to the resist intermediate film, or the organic thin film and the inorganic hard mask intermediate film by dry etching, using the transferred patterned resist intermediate film, or the inorganic hard mask intermediate film as a mask, transferring the pattern to the resist lower layer film by dry etching, using the above-mentioned metal-containing film-forming composition on the patterned resist lower layer film to coat a metal-containing film, filling the space between the patterns of the resist lower layer film with the metal-containing film, performing etchback on the metal-containing film coating the patterned resist lower layer film by chemical stripping or dry etching to expose the top surface of the patterned resist lower layer film, removing the resist intermediate film, or the hard mask intermediate film remaining on the top surface of the resist lower layer film by dry etching, removing the patterned resist lower layer film with the exposed surface by dry etching, forming an inverted pattern of the original pattern on the metal-containing film, and processing the substrate to be processed using the metal-containing film with the inverted pattern as a mask to form an inverted pattern on the substrate to be processed.

[0408] An example of forming a tone-inverted pattern is described below using Figure 2 as a specific example. As shown in (G) of Figure 2 , after forming a resist underlayer film 7 made of a coating-type organic underlayer film material on the processed layer 2 laminated on the processed substrate 1, a silicon-containing resist intermediate film 4 is formed, and a resist upper layer film 5 is formed thereon.

[0409] Then, as shown in (H) of Figure 2 , the used portion (exposed portion) 6 of the resist upper layer film 5 is exposed, and PEB and development are performed to form a resist upper layer film pattern 5a ( Figure 2 shown in (I) of Figure 2 ). Using the obtained resist upper layer film pattern 5a as a mask, the silicon-containing resist intermediate film 4 is etched using a CF-based gas to form a silicon-containing resist intermediate film pattern 4a ( Figure 2 shown in (J) of

[0410] ). After removing the resist upper layer film pattern 5a, using the obtained silicon-containing resist intermediate film pattern 4a as a mask, the resist underlayer film 7 made of a coating-type organic underlayer film material is subjected to oxygen plasma etching to form a resist underlayer film pattern 7a made of a coating-type organic underlayer film material ( Figure 2 shown in (K) of Figure 2 ). Figure 2 After coating the resist underlayer film pattern 7a made of a coating-type organic underlayer film material with the metal-containing film-forming composition of the present invention and performing heat treatment, a metal-containing film 8 is thereby formed, and the space between the resist underlayer film patterns 7a made of a coating-type organic underlayer film material is filled with the metal-containing film ( Figure 2 shown in (L) of Figure 2 ). Then, the metal-containing film 8 covering the resist underlayer film pattern 7a made of a coating-type organic underlayer film material is etched back using chemical stripping or dry etching to expose the top surface of the resist underlayer film pattern 7a made of a coating-type organic underlayer film material (

[0411] Figure 2 shown in (M) of Figure 2 ). Next, the silicon-containing resist intermediate film pattern 4a remaining on the top surface of the resist underlayer film pattern 7a made of a coating-type organic underlayer film material is removed by dry etching ( Figure 2 shown in (N) of Figure 2 ). Then, after removing the resist underlayer film pattern 7a made of a coating-type organic underlayer film material by dry etching and forming an inverted pattern of the original pattern on the metal-containing film (forming a metal-containing film pattern 8a that is the inversion of the resist underlayer film pattern) (

[0411] Figure 2 shown in (O) of Figure 2 ), using the metal-containing film pattern 8a that is the inversion of the resist underlayer film pattern as a mask, the aforementioned processed substrate is processed, and a tone-inverted pattern formation is formed on the aforementioned processed substrate (

[0411] Figure 2 shown in (P) of

[0411] As described above, when forming the underlayer film of the resist on the substrate to be processed, the method of using a coating-type organic underlayer film material or the method of forming the underlayer film of the resist by CVD method, ALD method, etc. can be adopted. Examples of the coating-type organic underlayer film material include resins and compositions shown in JP-A-2012-1687, JP-A-2012-77295, JP-A-2004-264710, JP-A-2005-043471, JP-A-2005-250434, JP-A-2007-293294, JP-A-2008-65303, JP-A-2004-205685, JP-A-2007-171895, JP-A-2009-14816, JP-A-2007-199653, JP-A-2008-274250, JP-A-2010-122656, JP-A-2012-214720, JP-A-2014-29435, International Publication WO2012 / 077640, International Publication WO2010 / 147155, International Publication WO2012 / 077640, International Publication WO2010 / 147155, International Publication WO2012 / 176767, JP-A-2005-128509, JP-A-2006-259249, JP-A-2006-259482, JP-A-2006-293298, JP-A-2007-316282, JP-A-2012-145897, JP-A-2017-119671, JP-A-2019-44022, etc.

[0412] In the above-described tone inversion type pattern forming method, after coating the resist underlayer film pattern with the composition for forming a metal-containing film, in order to expose the top surface of the resist underlayer film pattern, it is preferable to use a dry etching gas mainly composed of a chlorine-based gas to remove the metal-containing film. Thereafter, dry etching using a freon-based gas is used to remove the resist intermediate film or the hard mask intermediate film remaining on the above-described resist underlayer film, and dry etching using an oxygen-based gas is used to remove the resist underlayer film pattern whose surface has been exposed, thereby forming a metal-containing film pattern.

[0413] In the above-described tone-inversion type pattern formation method, the resist underlayer film pattern is preferably a structure having a height of 30 nm or more or a height difference. As described above, since the metal-containing film-forming composition of the present invention has excellent filling / planarization characteristics, even if there is a structure having a height of 30 nm or more or a height difference (concavo-convex) in the film to be processed, a flat hardened film can still be formed. The height of the structure or height difference of the resist underlayer film pattern is preferably 30 nm or more, more preferably 50 nm or more, and still more preferably 100 nm or more. In the method of inverting the resist underlayer film pattern having a pattern of the above height, by forming the metal-containing film-forming composition of the present invention and performing filling / planarization, pattern inversion / transfer can be performed with high precision, which is very desirable. Compared with a resist underlayer film using a known coating-type organic underlayer film material, it has excellent dry etching resistance to a freon-based gas. Therefore, by using the above metal-containing film-forming composition to invert the resist underlayer film pattern, a desired resist pattern can be formed with high precision on the film to be processed.

[0414] Examples

[0415] The following synthesis examples, comparative synthesis examples, examples, and comparative examples illustrate the present invention more specifically, but the present invention is not limited by them. In addition, the molecular weight and dispersity were determined as the polystyrene-converted weight-average molecular weight (Mw), number-average molecular weight (Mn) by gel permeation chromatography (GPC) using tetrahydrofuran as an eluent, and the dispersity (Mw / Mn) was determined.

[0416] [Synthesis Example]

[0417] In the following synthesis examples and comparative examples, the following tin compounds Sn: (Sn-1) to (Sn-5), raw material group X: (X1) to (X14), raw material group T: (TT1) to (TT5), and raw material group Z: (Z1) to (Z7) were used. The respective raw material groups are as follows. In addition, the following raw material compounds may sometimes have isomers, and one structure is shown as a representative.

[0418] Tin compound Sn:

[0419] [Chemical Formula 64]

[0420]

[0421] nBu represents n-butyl, tBu represents tert-butyl, Oc represents n-octyl, and Bn represents benzyl. The same applies hereinafter.

[0422] Raw material group X:

[0423] [Chemical Formula 65]

[0424]

[0425] Raw material group T:

[0426] [Chemical formula 66]

[0427]

[0428] Raw material group Z:

[0429] [Chemical formula 67]

[0430]

[0431] [Manufacturing example] Synthesis of raw material group T

[0432] Add the tin compound Sn and 1 equivalent of raw material X to toluene, react at 130 °C for 5 hours while removing water, then return to room temperature. Add the tin compound as needed and react again at 130 °C for 5 hours while removing water. Remove toluene under reduced pressure, suspend in methanol, and perform filtration and washing to obtain the compound of raw material group T.

[0433] Compound (TT1) is synthesized from the tin compound (Sn-3) and the compound represented by the following formula (X-15), compound (TT2) is synthesized from the tin compound (Sn-1) and compound (X-2), compound (TT3) is synthesized from the tin compound (Sn-2) and compound (X-6), compound (TT4) is synthesized from the tin compound (Sn-2) and compound (X-11), and compound (TT5) is synthesized from the tin compound (Sn-4) and compound (X-2).

[0434] [Chemical formula 68]

[0435]

[0436] [Synthesis example 1] Synthesis of metal-containing film-forming compound (P1)

[0437] (Reaction 1) Add 5.0 g of n-butyltin trichloride (Sn-5), 2.5 g of raw material (X-1), and 100 g of toluene, and react at 130 °C for 5 hours. Then, add 2.7 g of raw material (TT1) and react for an additional 3 hours. After the reaction is completed, remove toluene under reduced pressure, suspend in methanol, and perform filtration and washing to obtain compound (P1).

[0438] [Synthesis examples 2-14] Synthesis of metal-containing film-forming compounds (P2) to (P14)

[0439] Change raw material group X and raw material group T or raw material group Z as shown in Table 1, and perform the same operations as in Synthesis example 1 to obtain metal-containing film-forming compounds (P2) to (P14).

[0440] [Table 1]

[0441]

[0442] [Chemical Formula 69]

[0443]

[0444] [Synthesis of Metal-Containing Film-Forming Compound (R-1) for Comparative Example]

[0445] 5.0 g of tin compound (Sn-1), 8.6 g of raw material group P (Z-1), and 100 g of toluene were added, and the reaction was carried out for 7 hours while removing water at 130°C. After the reaction, the solvent was removed under reduced pressure to obtain (R-1).

[0446] [Chemical Formula 70]

[0447]

[0448] [Synthesis of Metal-Containing Film-Forming Compound (R-2) for Comparative Example]

[0449] 5.0 g of tin compound (Sn-1), 6.8 g of raw material group X (X-14), and 50 g of toluene were added, and the reaction was carried out for 7 hours while removing water at 130°C. After the reaction, the solvent was removed under reduced pressure to obtain (R-2).

[0450] [Chemical Formula 71]

[0451]

[0452] [Weight-Average Molecular Weight and Dispersity]

[0453] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) of the above compounds (P1) to (P14), (R-1), and (R-2) were determined. The results are shown in Table 2. In addition, the weight-average molecular weight Mw and number-average molecular weight Mn are polystyrene conversion values obtained by the GPC method using tetrahydrofuran, and the dispersity was calculated therefrom.

[0454] [Table 2]

[0455]

[0456]

[0457] [Synthesis of Metal-Containing Film-Forming Compound (R-3) for Comparative Example]

[0458] A tin compound reported in [Synthesis Example 8] of Japanese Patent No. 7028940 was synthesized as a metal-containing compound expected to be used in a photoresist.

[0459] Dissolve 3 g of isopropyltriphenyltin and 1.4 g of succinic acid in 20 ml of acetonitrile and reflux for 24 hours. After the reaction, remove the solvent under reduced pressure to obtain a tin-containing compound (R-3).

[0460] [Chemical formula 72]

[0461]

[0462] [Synthesis of metal-containing film-forming compound (R-4) for comparative example]

[0463] Add 10 g of catechol, 6.6 g of formaldehyde, and 30 g of PGME (propylene glycol monomethyl ether), and homogenize at an internal temperature of 100 °C. Then, slowly add dropwise a mixed solution of 0.2 g of p-toluenesulfonic acid monohydrate and 3.0 g of PGME that has been previously mixed and homogenized, and carry out a reaction at an internal temperature of 120 °C for 8 hours. After the reaction is completed, cool to room temperature, add 150 g of ultrapure water while stirring, let stand for 1 hour, and fractionate the upper layer. Then dissolve it in 30 g of PGME, and repeat the same operation 2 times. Thereafter, add 300 ml of MIBK (methyl isobutyl ketone), wash 4 times with 200 ml of pure water, and dry the organic layer under reduced pressure. Then, add 20 g of tin raw material (Sn-1) and 300 g of toluene, and stir at 130 °C for 8 hours. Remove the solvent after the reaction under reduced pressure to obtain (R-4).

[0464] [Chemical formula 73]

[0465]

[0466] [Synthesis of metal-containing film-forming compound (R-5) for comparative example]

[0467] Add 5 g of glycerol monomethacrylate, 0.7 g of V-601, and 20 g of MEK (methyl ethyl ketone), conduct nitrogen bubbling, and stir at 79 °C for 20 hours. After cooling to room temperature, add the polymer solution to 100 g of IPE (diisopropyl ether), and pour off the upper layer. Add 30 g of DMF and 7.4 g of (Sn-1), and react at 130 °C for 8 hours. After the reaction, remove DMF under reduced pressure, add IPE and filter to obtain (R-5).

[0468] [Chemical formula 74]

[0469]

[0470] [Synthesis of metal-containing film-forming compound (R-6) for comparative example]

[0471] Synthesize the titanium compound reported in [Synthesis Example A-II] of Japanese Patent No. 6189758 as a compound having a different metal from the metal-containing film-forming compound of the present invention.

[0472] To a solution of 284 g of titanium tetraisopropoxide (manufactured by Tokyo Chemical Industry Co., Ltd.) in 500 g of IPA (isopropyl alcohol), a solution of 27 g of deionized water in 500 g of IPA was added dropwise with stirring at room temperature over 2 hours. 120 g of 2-methyl-2,4-pentanediol was added to the resulting solution, and the mixture was stirred at room temperature for 30 minutes. The solution was concentrated under reduced pressure at 30 °C and then heated to 60 °C, and heating was continued under reduced pressure until no more distillate was observed. When no more distillate was observed, 1,200 g of PGMEA was added, and the mixture was heated at 40 °C under reduced pressure until no more IPA was distilled off, to obtain 1,000 g of a PGMEA solution of a titanium-containing compound (R-6) (compound concentration: 20% by mass).

[0473] [Synthesis of Organic Film-Forming Resin (R-7) for Comparative Example]

[0474] Under a nitrogen atmosphere, 160.2 g of 1,5-dihydroxynaphthalene, 56.8 g of formaldehyde, and 300 g of PGME (propylene glycol monomethyl ether) were added and homogenized at an internal temperature of 100 °C. Thereafter, a mixed solution of 8.0 g of p-toluenesulfonic acid monohydrate and 8.0 g of PGME, which had been previously mixed and homogenized, was slowly added dropwise, and the reaction was carried out at an internal temperature of 80 °C for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, 2,000 ml of MIBK was added, washing was carried out 6 times with 500 ml of pure water, and the organic layer was dried under reduced pressure. 300 g of THF was added to the residue to form a homogeneous solution, and crystallization was carried out in 2,000 g of hexane. The precipitated crystals were separated by filtration, washed twice with 500 g of hexane, and recovered. The recovered crystals were vacuum-dried at 70 °C to obtain resin (R-7).

[0475] When the weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, the following results were obtained.

[0476] (R-7): Mw = 3,300, Mw / Mn = 2.54

[0477] [Chemical Formula 75]

[0478]

[0479] "Evaluation of Solvent Solubility and Heat Resistance"

[0480] The solvent solubility and heat resistance of the metal-containing compound were evaluated.

[0481] The compounds (P1) to (P14) synthesized in Synthesis Examples 1 to 14 and the comparative example compounds (R-1) to (R-6) were each prepared into a 15.0 wt% solution of propylene glycol monomethyl ether acetate (PGMEA) and cyclohexanone (CyHO). After stirring for 24 h, those that were completely dissolved were rated as 〇, those with partial undissolution were rated as △, and those that were completely suspended were rated as ×. Also, 3.0 mg was weighed respectively, and using Thermo plus EVO2 of RIGAKU, the temperature was raised from 30 °C to 300 °C in the atmosphere at a rate of 10 °C / min. At this time, those with a weight reduction of 40% or less when the temperature was raised to 300 °C were rated as A, those with 40 - 60% were rated as B, and those with a weight reduction of more than 60% were rated as C. Their results are shown in Table 3.

[0482] [Table 3]

[0483]

[0484] As shown in Table 3, it was confirmed that all of the metal-containing film-forming compounds (P1) to (P14) of the present invention could be prepared as solutions with cyclohexanone and had sufficient solubility. Also, it was confirmed that those having a large number of organic chains in the main chain and those sealed with organic groups at the ends could also be prepared as solutions with PGMEA and exhibited excellent solvent solubility. Similarly, for the comparative example compounds of the compound group in which some requirements of the present invention were removed, the results of the same solubility were shown, but among the repeating units of the polymer, (R-4) and (R-5) with the structure of all-introduced tin had no solubility. Also, in the TG-DTA measurement, the weight reduction of all of the compounds of the present invention was 40% or less when the temperature was raised to 300 °C, but among the comparative example compounds, (R-2) had a 49% reduction, (R-3) had a 68% reduction, and (R-6) had a 56% reduction. Compared with them, it was confirmed that the compounds of the present invention had excellent heat resistance.

[0485] [Metal-containing film-forming composition UDL-1]

[0486] The metal-containing film-forming compound (P1) was dissolved in a solvent of cyclohexanone (CyHO) containing 0.5 mass% of the surfactant FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) at the ratio shown in Table 4 and filtered through a 0.2 μm filter membrane to prepare a metal-containing film-forming composition (UDL-1).

[0487] [Preparation of metal-containing film-forming compositions (UDL-2 to 21), comparative example metal-containing film-forming compositions (comparative example UDL-1 to 5)]

[0488] Change the types and contents of the respective components as shown in Table 4. Except for this, perform the operations in the same manner as UDL-1 to prepare each liquid medicine. In addition, in Table 4, "-" indicates that the corresponding component is not used. The crosslinking agent uses the following formula (C-1), the high-boiling solvent (B2-1) uses 1,6-diacetoxyhexane: boiling point 260 °C, and the polymer (E-1) for promoting fluidity is used, and the thermal acid generator (TAG) uses the following formula (F-1).

[0489] [Crosslinking agent]

[0490] The crosslinking agent (C-1) used in the metal-containing film-forming composition is as follows.

[0491] [Chemical formula 76]

[0492]

[0493] [Synthesis example of polymer for promoting fluidity] Synthesis of the polymer (E-1) for promoting fluidity

[0494] Under a nitrogen atmosphere, add 20.0 g of cresol novolak resin, 27.6 g of potassium carbonate, and 100 g of DMF, and make a homogeneous dispersion at an internal temperature of 50 °C. Slowly add 11.9 g of propargyl bromide, and carry out a reaction at an internal temperature of 50 °C for 24 hours. Add 300 ml of methyl isobutyl ketone and 300 g of pure water to the reaction solution to dissolve the precipitated salt, and then remove the separated aqueous layer. Then, wash the organic layer 6 times with 100 g of 3% nitric acid aqueous solution and 100 g of pure water, and then dry the organic layer under reduced pressure to obtain the resin (E-1).

[0495] When the weight-average molecular weight (Mw) and dispersity (Mw / Mn) are determined by GPC, the results are as follows.

[0496] (E-1): Mw = 8,500, Mw / Mn = 3.46

[0497] [Chemical formula 77]

[0498]

[0499] [Thermal acid generator]

[0500] The thermal acid generator (F-1) used in the metal-containing film-forming composition is as follows.

[0501] [Chemical formula 78]

[0502]

[0503] [Table 4]

[0504]

[0505] [Film-forming property test]

[0506] The metal-containing film-forming compositions (UDL-1 to 21, Comparative Example UDL-1 to 4) prepared above were coated on a silicon substrate, calcined at 180 °C for 60 seconds, and then additionally calcined at 250 °C for 60 seconds, and the film thickness (a [nm]) was measured. In addition, the film thickness from the center part to the outer peripheral part of the substrate was measured, the film thickness difference Range (b [nm]) between the maximum film thickness and the minimum film thickness was obtained, and the in-plane uniformity ((b / a)×100) was obtained.

[0507] In addition, PGMEA solvent was dispensed thereon, left for 30 seconds and spin-dried, and baked at 100 °C for 60 seconds to evaporate PGMEA (Rework), and the film thickness (c [nm]) was measured. The film thickness difference before and after PGMEA treatment (residual film ratio: (c / a)×100) was obtained. The results are shown in Table 5 below.

[0508] [Table 5]

[0509]

[0510] As shown in Table 5, it was confirmed that the in-plane uniformity of the metal-containing film-forming compositions (Examples 1-1 to 1-21) of the present invention after high-temperature additional baking treatment at 250 °C was 5.0% or less, and the films had excellent film-forming properties. On the other hand, in Comparative Examples 1-1 to 1-2 using Comparative Example Compounds (R-1) and Comparative Example Compounds (R-2) which are monomolecular tin compounds, the in-plane uniformity was relatively good, but the results were inferior to those of the Examples using the compound group of the present invention. It is considered that this is because the radical active units of the Sn-alkyl bond are few, so crosslinking by radicals cannot be efficiently caused, and the film is uneven due to sublimates and decomposition products. Also, in Comparative Example 1-3 using Comparative Example Compound (R-3) which has many tin atoms in one molecule but no diol unit and is composed only of esters, due to the influence of insufficient molecular weight, the result is that the film has large unevenness. In Comparative Example 1-4 of Comparative Example UDL-4 using the titanium compound (R-6) reported in [Synthesis Example A-II] of Japanese Patent No. 6189758, a film with many unevennesses and poor film-forming properties with an in-plane uniformity exceeding 5.0% after baking treatment was formed. It is speculated that this is because the titanium compound lacks heat resistance, has many sublimates, and has a large volume shrinkage, etc.

[0511] Also, in Examples 1-15 to 1-18 using UDL-15 to 18 with the crosslinking agent (C-1) added, there is a tendency for the in-plane uniformity to be improved compared to Examples 1-1, 5, 7, and 13 using UDL-1, 5, 7, and 13 without the addition. It is considered that this is because the crosslinking reaction can be carried out more efficiently by the crosslinking agent, and the generation of sublimates and decomposition products can be suppressed. Also, in Example 1-20 using UDL-20 with the acid generator (F-1) added, the residual film rate after rework is higher than that in Example 1-12 without the addition, suggesting that the crosslinking reaction proceeds further. Also, it was confirmed that there is not much difference in the in-plane uniformity and the residual film rate after rework when comparing other examples with the addition of a fluidity promoter and a high-boiling solvent to those without the addition.

[0512] [Landfill property evaluation]

[0513] The above metal-containing film-forming compositions (UDL-1 to 21) and Comparative Examples UDL-3 and 4 were respectively coated on a SiO2 wafer substrate having a dense line & space pattern (line width of the line: 40 nm, line depth: 120 nm, distance between the centers of two adjacent lines: 80 nm), and heated on a hot plate at 250 °C for 60 seconds to form a metal-containing film with a film thickness of 100 nm. The substrate used has a base substrate 9 (SiO2 wafer substrate) with a dense line & space pattern as shown in Figure 3 (Q) (top view) and (R) (cross-sectional view). 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 filled the height difference substrate. The results are shown in Table 6. When using a metal-containing film-forming composition with poor landfill properties, in this evaluation, the height difference substrate could not be filled smoothly. When using a metal-containing film-forming composition with good landfill properties, in this evaluation, it could fill the spaces between the lines of the base substrate 9 with a dense line & space pattern without gaps as shown in Figure 3 (S). ○ indicates that it can be filled without large voids, △ indicates that it can be filled but large voids are generated, and × indicates that it cannot be filled.

[0514] [Table 6]

[0515]

[0516]

[0517] As shown in Table 6, it was confirmed that in Examples 2-1 to 2-21 using the resist metal-containing film-forming composition of the present invention, when baking was carried out at 250°C, voids were not generated, dense line & space patterns could be filled, and good filling characteristics were exhibited. On the other hand, in Comparative Example 2-1 using Comparative Example UDL-3 with poor film-forming properties, or in Comparative Example 2-2 using the titanium compound reported in [Synthesis Example A-II] of Japanese Patent No. 6189758, filling could not be achieved in Comparative Example 2-1, and voids were observed at the bottom of the pattern in Comparative Example 2-2. It is presumed that this is because, as observed in the above heat resistance evaluation and film-forming property evaluation of the compounds of the present invention, the sublimates due to high-temperature baking are few and the volume shrinkage is small, so voids are not generated and height differences can be filled. On the other hand, in Comparative Examples UDL-3 and 4 lacking heat resistance, there are many sublimates and the volume shrinkage is also large, resulting in the generation of voids or inability to fill.

[0518] [Tin content rate, etching resistance test]

[0519] The above-prepared metal-containing film-forming compositions (UDL-1, 2, 5, 7, 13, 15, 16, 17, 19) and Comparative Examples UDL-1 to 2 and 5 with relatively good in-plane uniformity were coated on a silicon substrate, heated on a hot plate at 250°C for 60 seconds to form a metal-containing film, and the elemental ratio on the surface was determined using XPS K-ALPHA Surface Analysis (manufactured by Thermo SCIENTIFIC) and converted to mass%. In addition, an etching test under CF-based gas and O2-based gas was carried out under the following conditions to determine the film thickness difference of the film before and after etching. The results are shown in Table 7. Also, for etching, a dry etching apparatus TE-8500 manufactured by Tokyo Electron Limited was used. The CF4-based gas etching conditions are as shown below.

[0520]

[0521] The O2-based gas etching conditions are as shown below.

[0522]

[0523] [Table 7]

[0524]

[0525] As shown in Table 7, in Examples 3-1 to 3-9 using the metal-containing film-forming composition of the present invention, regardless of the presence or absence of additives, the tin content rate of the calcined film exceeded 60 wt%. On the other hand, in Comparative Examples 3-1 and 3-2 using Comparative Examples UDL-1 and 2 in which only 1 tin atom is present in one molecule, the tin content rate was lower than 55 wt%, showing a difference in tin content rate. In addition, it was also confirmed that in Examples 3-1 to 3-5 using UDL-1, 2, 5, 7, and 13 without additives, the tin content rate was 65 wt% or more, and the higher ones exceeded 70 wt%. It can be seen that the calcined film has a high tin content rate, and it can be confirmed that many tin atoms are contained in one molecule, which will result in a film with a high tin content rate, indicating that secondary electron release due to EUV light absorption can be expected. In addition, in the etching resistance evaluation, the higher the tin content rate, the better the etching resistance for both CF-based gases and O2-based gases. In particular, regarding O2 etching, compared with Comparative Example 3-3 of an organic lower layer film without tin, the result was a significant improvement in etching resistance.

[0526] From the above, it can be seen that the metal oxide film-forming compound of the present invention is an organotin compound that highly combines heat resistance and a high tin content rate. Therefore, the metal-containing film-forming composition using it can provide a resist lower layer film material that has excellent dry etching resistance to known organic lower layer film materials, and at the same time combines film-forming properties and filling properties, and is extremely useful as a resist lower layer film material used in the multilayer resist method and a reversal agent used in the tone inversion etching method.

[0527] This specification includes the following aspects.

[0528] [1]: A metal-containing film-forming compound, characterized in that the compound is a polymer containing any one or both of the repeating units represented by the following general formula (P-1) or (P-2).

[0529] [Chemical formula 79]

[0530]

[0531] In the aforementioned general formulas (P-1) and (P-2), R1 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. W1 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms, and the aforementioned hydrocarbon group contains oxygen, nitrogen, or sulfur atoms as heteroatoms, and may also form an ether bond, a carbonyl group, an ester group, an amide group, and may also form a heterocyclic structure with the aforementioned heteroatoms spaced apart. R2 represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms containing one or more double bonds or triple bonds, a hydroxyl group, an amino group, a halogen atom, s1 is an integer of 0 to 1, and n1 is an integer of 0 to 1. Also, these elements in the repeating unit may also include a variety of different ones. W2 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms, and the aforementioned hydrocarbon group contains oxygen, nitrogen, or sulfur atoms as heteroatoms, and may also form an ether bond, a carbonyl group, an ester group, an amide group, and may also form a heterocyclic structure with the aforementioned heteroatoms spaced apart. s2 is an integer of 0 to 1. s3 is 1 or 2, and when s3 is 1, R3 is a hydrogen atom or a hydrocarbon group having a hydroxyl group and 1 to 10 carbon atoms, and when s3 is 2, R3 is an oxygen atom, and together with the carbon atom to which it is bonded, it forms a carbonyl group. W2 and R3 may also be bonded to each other to form a ring structure. Also, these elements in the repeating unit may also include a variety of different ones.

[0532] [2]: A metal-containing film-forming compound as in [1], wherein the metal-containing film-forming compound is a polymer containing a repeating unit represented by the aforementioned general formula (P-1), and in the aforementioned general formula (P-1), W1 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms that may also contain a hydroxyl group or an amino group (the aforementioned hydrocarbon group contains oxygen, nitrogen, or sulfur atoms, and may also form an ether bond, a carbonyl group, an ester group), or is any one of the groups represented by the following general formulas (W1-1) to (W1-4).

[0533] [Chemical formula 80]

[0534]

[0535] In the above general formulas (W1-1) to (W1-4), R W is a divalent organic group having 1 to 23 carbon atoms, #1 represents the bonding part with the ester, and #2 represents the bonding part with the benzene ring.

[0536] [3]: A metal-containing film-forming compound as in [1] or [2], wherein the metal-containing film-forming compound is a polymer containing a repeating unit represented by the aforementioned general formula (P-2), and in the aforementioned general formula (P-2), W2 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms which may contain a hydroxyl group or an amino group, or is a cyclic hydrocarbon group formed by bonding to R3 (the aforementioned hydrocarbon group contains an oxygen atom, a nitrogen atom, a sulfur atom, and may form an ether bond, a carbonyl group, an ester group), or is any one of the groups represented by the following general formulas (W2-1) to (W2-4).

[0537] [Chemical formula 81]

[0538]

[0539] In the above general formulas (W2-1) to (W2-4), R W is a divalent organic group having 1 to 23 carbon atoms, and #1 and #2 respectively represent the bonding parts to an ester and a carbon atom.

[0540] [4]: A metal-containing film-forming compound as in [2], wherein R in the aforementioned general formulas (W1-1) to (W1-4) W is an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

[0541] [5]: A metal-containing film-forming compound as in [4], wherein the aforementioned R W is a group represented by the following general formula (1).

[0542] [Chemical formula 82]

[0543]

[0544] In the aforementioned general formula (1), R a , R b and R c are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and R a and R b may also bond to form a cyclic substituent. *1 and *2 respectively represent the bonding parts to a carbonyl group, and *1 and *2 may also be reversed.

[0545] [6]: A metal-containing film-forming compound as in [3], wherein R in the aforementioned general formulas (W2-1) to (W2-4) W is an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

[0546] [7]: A metal-containing film-forming compound as in [6], wherein the aforementioned R W is a group represented by the following general formula (1).

[0547] [Chemical formula 83]

[0548]

[0549] In the above general formula (1), R a , R b and R c are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R a and R b may also be bonded to form a cyclic substituent. *1 and *2 respectively represent the bonding parts to the carbonyl group, and *1 and *2 may also be inverted.

[0550] [8]: A metal-containing film-forming compound according to any one of [1] to [7], wherein the terminal structure of the polymer having the repeating unit of the above general formula (P-1) is the following general formula (T-1), or the terminal structure of the polymer having the repeating unit of the above general formula (P-2) is the following general formula (T-2).

[0551] [Chemical formula 84]

[0552]

[0553] In the above general formulas (T-1) to (T-2), R1, R2, R3, W1, W2, s1, s2 and s3 are the same as those in the above general formulas (P-1) to (P-2).

[0554] [9]: A metal-containing film-forming compound according to any one of [1] to [7], wherein the terminal structure of the polymer having the repeating unit of the above general formula (P-1) or (P-2) is *-OC(=O)R, and R is a monovalent organic group, and * represents the bonding part to the Sn atom in the polymer.

[0555]

[10] : A metal-containing film-forming compound according to [9], wherein in the above terminal structure *-OC(=O)R, R is any one of the groups represented by the following general formulas (A-1) to (A-4), the following general formula (3) and the following general formula (4).

[0556] [Chemical formula 85]

[0557]

[0558] In the above general formulas (A-1) to (A-4), Y A1 , Y A2 may be the same or different from each other, and are a substituted or unsubstituted divalent organic group having 1 to 23 carbon atoms and being saturated or having 2 to 23 carbon atoms and being unsaturated, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkylene group having 7 to 31 carbon atoms. R Ais a hydrogen atom, a substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms and being saturated or having 2 to 20 carbon atoms and being unsaturated, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, R A1 is an organic group represented by the following general formula (2) in which a protecting group is removed by the action of either or both of an acid and heat to generate one or more hydroxyl groups or carboxyl groups, and * represents a bonding portion to a carbonyl group.

[0559] [Chemical formula 86]

[0560]

[0561] In the aforementioned general formula (2), R A2 is an organic group in which a protecting group is removed by the action of either or both of an acid and heat, and * represents a bonding portion to Y A1 or Y A2 's bonding portion.

[0562] [Chemical formula 87]

[0563]

[0564] In the aforementioned general formula (3), X is a divalent organic group having 1 to 31 carbon atoms, B is the following general formula (B), and * represents a bonding portion to a carbonyl group.

[0565] [Chemical formula 88]

[0566] B = *-Y B -R B (B)

[0567] In the aforementioned general formula (B), Y B is a substituted or unsubstituted divalent organic group having 1 to 20 carbon atoms and being saturated or having 2 to 20 carbon atoms and being unsaturated, a substituted or unsubstituted divalent arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted divalent arylalkylene group having 7 to 31 carbon atoms, R B is a hydroxyl group or any one of the structures represented by the following general formulas (B-1) to (B-3).

[0568] [Chemical formula 89]

[0569]

[0570] In the aforementioned general formulas (B-1) to (B-3), R B1 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bonding portion to Y B 's bonding portion.

[0571] [Chemical formula 90]

[0572]

[0573] In the general formula (4) above, X is a divalent organic group having 1 to 31 carbon atoms, C is any one of the groups represented by the following general formulas (C-1) to (C-4), and * represents the bonding portion to the carbonyl group.

[0574] [Chemical formula 91]

[0575]

[0576] In the general formulas (C-1) and (C-3) above, R C1 is a hydrogen atom or a methyl group, and in the same formula, they may be the same or different from each other. In (C-3) and (C-4), R C2 is a hydrogen atom, a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms with or without substitution, an aryl group having 6 to 30 carbon atoms with or without substitution, or an arylalkyl group having 7 to 31 carbon atoms with or without substitution. * represents the bonding portion to the carbonyl group.

[0577]

[11] : A metal-containing film-forming compound as in

[10] , wherein Y in the general formulas (A-1) to (A-4) above A1 , X in the general formula (3) above, or X in the general formula (4) above is an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

[0578]

[12] : A metal-containing film-forming compound as in

[10] , wherein Y in the general formulas (A-1) to (A-4) above A1 , X in the general formula (3) above, or X in the general formula (4) above is a group represented by the following general formula (1).

[0579] [Chemical formula 92]

[0580]

[0581] In the general formula (1) above, R a , R b and R c are a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and R a and R b may also be bonded to form a cyclic substituent. *1 and *2 each represent the bonding portion to the carbonyl group, and *1 and *2 may also be inverted.

[0582]

[13] : A metal-containing film-forming composition that functions as an underlayer film material for a resist used in semiconductor manufacturing, characterized by containing:

[0583] (a) A metal-containing film-forming compound as in any one of [1] to

[12] , and

[0584] (b) Organic solvent.

[0585]

[14] : A metal-containing film-forming composition as in

[13] , wherein the composition is a metal-containing film-forming composition that can be used as an underlayer resist film used in a multilayer resist method, and further contains one or more of (c) a crosslinking agent, (d) a surfactant, (e) a fluidity promoter, and (f) an acid generator.

[0586]

[15] : A metal-containing film-forming composition as in

[13] or

[14] , wherein the (b) organic solvent is a mixture of one or more organic solvents with a boiling point below 180 °C and one or more organic solvents with a boiling point of 180 °C or higher.

[0587]

[16] : A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by having the following steps:

[0588] (I-1) Coating a metal-containing film-forming composition as in any one of

[13] to

[15] on the substrate to be processed and then performing heat treatment to thereby form a metal-containing film.

[0589] (I-2) Forming an upper resist film on the aforementioned metal-containing film using a photoresist material.

[0590] (I-3) After pattern exposure of the aforementioned upper resist film, developing with a developer solution and forming a pattern on the aforementioned upper resist film.

[0591] (I-4) Using the aforementioned patterned upper resist film as a mask and transferring the pattern to the aforementioned metal-containing film by dry etching, and

[0592] (I-5) Using the aforementioned patterned metal-containing film as a mask, processing the aforementioned substrate to be processed and forming a pattern on the aforementioned substrate to be processed.

[0593]

[17] : A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by having the following steps:

[0594] (II-1) Coating a metal-containing film-forming composition as in any one of

[13] to

[15] on the substrate to be processed and then performing heat treatment to thereby form a metal-containing film.

[0595] (II-2) Forming a resist intermediate film on the aforementioned metal-containing film.

[0596] (II-3) Forming an upper resist film on the aforementioned resist intermediate film using a photoresist material.

[0597] (II-4) After pattern exposure of the aforementioned upper resist film, develop it with a developer to form a pattern in the aforementioned upper resist film.

[0598] (II-5) Using the aforementioned patterned upper resist film as a mask, transfer the pattern to the aforementioned intermediate resist film by dry etching.

[0599] (II-6) Using the aforementioned intermediate resist film with the transferred pattern as a mask, transfer the pattern to the aforementioned metal-containing film, and

[0600] (II-7) Using the aforementioned patterned metal-containing film as a mask, process the aforementioned substrate to be processed and form a pattern on the aforementioned substrate to be processed.

[0601]

[18] : A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by having the following steps:

[0602] (III-1) After coating the metal-containing film forming composition according to any one of

[13] to

[15] on the substrate to be processed, perform heat treatment to thereby form a metal-containing film.

[0603] (III-2) Form an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the aforementioned metal-containing film.

[0604] (III-3) Form an organic thin film on the aforementioned inorganic hard mask intermediate film.

[0605] (III-4) Use a photoresist material to form an upper resist film on the aforementioned organic thin film.

[0606] (III-5) After pattern exposure of the aforementioned upper resist film, develop it with a developer to form a pattern in the aforementioned upper resist film.

[0607] (III-6) Using the aforementioned patterned upper resist film as a mask, transfer the pattern to the aforementioned organic thin film and the aforementioned inorganic hard mask intermediate film by dry etching.

[0608] (III-7) Using the aforementioned inorganic hard mask intermediate film with the transferred pattern as a mask, transfer the pattern to the aforementioned metal-containing film, and

[0609] (III-8) Using the aforementioned patterned metal-containing film as a mask, process the aforementioned substrate to be processed and form a pattern on the aforementioned substrate to be processed.

[0610]

[19] : A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by having the following steps:

[0611] (IV-1) Form a lower resist film on the substrate to be processed.

[0612] (IV-2) Coat the composition for forming a metal-containing film according to any one of

[13] to

[15] on the above-mentioned lower resist film and then perform heat treatment to form a metal-containing film.

[0613] (IV-3) Form an upper resist film on the above-mentioned metal-containing film using a photoresist material, or form an organic conformal film on the above-mentioned metal-containing film by spin coating and then form an upper resist film on it using a photoresist material.

[0614] (IV-4) After pattern exposure of the above-mentioned upper resist film, develop it with a developer and form a pattern on the above-mentioned upper resist film.

[0615] (IV-5) Use the above-mentioned patterned upper resist film as a mask and transfer the pattern to the above-mentioned metal-containing film, or the above-mentioned organic conformal film and the above-mentioned metal-containing film by dry etching.

[0616] (IV-6) Use the above-mentioned metal-containing film with the transferred pattern as a mask and transfer the pattern to the above-mentioned lower resist film, and

[0617] (IV-7) Use the above-mentioned lower resist film with the formed pattern as a mask to process the above-mentioned substrate to be processed and form a pattern on the above-mentioned substrate to be processed.

[0618]

[20] : A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by having the following steps:

[0619] (V-1) Form a lower resist film on the substrate to be processed.

[0620] (V-2) Form a resist intermediate film on the above-mentioned lower resist film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film and an organic thin film.

[0621] (V-3) Form an upper resist film on the above-mentioned resist intermediate film, or on the combination of the inorganic hard mask intermediate film and the organic thin film using a photoresist material.

[0622] (V-4) After pattern exposure of the above-mentioned upper resist film, develop it with a developer and form a pattern on the above-mentioned upper resist film.

[0623] (V-5) Use the above-mentioned patterned upper resist film as a mask and transfer the pattern to the above-mentioned resist intermediate film, or the above-mentioned organic thin film and the above-mentioned inorganic hard mask intermediate film by dry etching.

[0624] (V-6) Using the resist intermediate film or inorganic hard mask intermediate film with the transferred pattern as a mask, and transferring the pattern to the resist lower layer film by dry etching.

[0625] (V-7) Coating the resist lower layer film with the formed pattern with the metal-containing film-forming composition according to any one of

[13] to

[15] , and then performing heat treatment to coat the metal-containing film and fill the spaces between the patterns of the resist lower layer film with the metal-containing film.

[0626] (V-8) Etching back the metal-containing film covering the resist lower layer film with the formed pattern by chemical stripping or dry etching to expose the top surface of the resist lower layer film with the formed pattern.

[0627] (V-9) Removing the resist intermediate film or hard mask intermediate film remaining on the top surface of the resist lower layer film by dry etching.

[0628] (V-10) Removing the resist lower layer film with the formed pattern whose surface has been exposed by dry etching, and forming an inverted pattern of the original pattern on the metal-containing film, and

[0629] (V-11) Using the metal-containing film with the formed inverted pattern as a mask to process the substrate to be processed, and forming an inverted pattern on the substrate to be processed.

[0630]

[21] : The pattern forming method according to

[18] or

[20] , which forms the inorganic hard mask intermediate film by CVD method or ALD method.

[0631] In addition, the present invention is not limited to the above embodiments. The above embodiments are illustrative, and those having substantially the same constitution as the technical idea described in the claims of the present invention and exhibiting the same effects are all included in the technical scope of the present invention.

[0632] Explanation of reference numerals

[0633] 1: Substrate to be processed

[0634] 2: Layer to be processed

[0635] 2a: Pattern (pattern formed on the layer to be processed)

[0636] 3: Metal-containing resist lower layer film

[0637] 3a: Metal-containing resist lower layer film pattern

[0638] 4: Silicon-containing resist intermediate film

[0639] 4a: Silicon-containing resist intermediate film pattern

[0640] 5: Upper resist film

[0641] 5a: Upper resist film pattern

[0642] 6: Exposed part

[0643] 7: Resist lower film composed of coated organic lower film material

[0644] 7a: Resist lower film pattern composed of coated organic lower film material

[0645] 8: Metal-containing film

[0646] 8a: Metal-containing film pattern obtained by inverting the resist lower film pattern

[0647] 9: Substrate having dense lines & spaces

[0648] 10: Metal-containing resist lower film

Claims

1. A metal-containing film-forming compound, characterized in that: The compound is a polymer containing either or both of the repeating units represented by the following general formula (P-1) or (P-2); In the general formulae (P-1) and (P-2), R1 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms and containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms; W1 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms, and the hydrocarbon group contains an oxygen atom, a nitrogen atom or a sulfur atom as a heteroatom, and may form an ether bond, a carbonyl group, an ester group or an amide group, and may also form a heterocyclic structure with the heteroatom interrupted; R2 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms and containing one or more double bonds or triple bonds; or an unsubstituted aliphatic unsaturated hydrocarbon group having 2 to 20 carbon atoms, a hydroxyl group, an amino group, or a halogen atom, s1 is an integer of 0 to 1, and n1 is an integer of 0 to 1; further, these elements in the repeating unit may also include multiple different ones; W2 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms, and the hydrocarbon group contains an oxygen atom, a nitrogen atom, or a sulfur atom as a heteroatom, and may also form an ether bond, a carbonyl group, an ester group, or an amide group, and may also form a heterocyclic structure by interrupting the heteroatom; s2 is an integer of 0 to 1; s3 is 1 or 2, and when s3 is 1, R3 is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms and having a hydroxyl group, and when s3 is 2, R3 is an oxygen atom, and together with the carbon atom to which it is bonded, it forms a carbonyl group, and W2 and R3 may also be bonded to each other to form a ring structure; further, these elements in the repeating unit may also include multiple different ones.

2. The metal-containing film-forming compound according to claim 1, wherein The metal-containing film-forming compound is a polymer containing a repeating unit represented by the general formula (P-1), and in the general formula (P-1), W1 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms (the hydrocarbon group contains an oxygen atom, a nitrogen atom, a sulfur atom, and may also form an ether bond, a carbonyl group, or an ester group) which may also contain a hydroxyl group or an amino group, or is any one of the groups represented by the following general formulas (W1-1) to (W1-4); In the general formulas (W1-1) to (W1-4), R W It is a divalent organic group having 1 to 23 carbon atoms, #1 represents a bonding portion with an ester, and #2 represents a bonding portion with a benzene ring.

3. The metal-containing film-forming compound according to claim 1, wherein The metal-containing film-forming compound is a polymer containing a repeating unit represented by the general formula (P-2), and in the general formula (P-2), W2 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms which may also contain a hydroxyl group or an amino group, or a cyclic hydrocarbon group bonded to R3 (the hydrocarbon group contains an oxygen atom, a nitrogen atom, a sulfur atom, and may also form an ether bond, a carbonyl group, or an ester group), or any one of the groups represented by the following general formulas (W2-1) to (W2-4); In the general formulas (W2-1) to (W2-4), R W It is a divalent organic group having 1 to 23 carbon atoms, and #1 and #2 represent the bonding part with an ester and a carbon atom, respectively.

4. The metal-containing film-forming compound according to claim 2, wherein In the general formulas (W1-1) to (W1-4), R W It is an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

5. The metal-containing film-forming compound according to claim 4, wherein The R W is a group represented by the following general formula (1); In the general formula (1), R a , R b and R c is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, R a With R b It can also bond to form a cyclic substituent; *1 and *2 represent the bonding part with the carbonyl group, respectively, and *1 and *2 can also be reversed.

6. The metal-containing film-forming compound according to claim 3, wherein In the general formulas (W2-1) to (W2-4), R W It is an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

7. The metal-containing film-forming compound according to claim 6, wherein The R W is a group represented by the following general formula (1); In the general formula (1), R a , R b and R c is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, R a With R b It can also bond to form a cyclic substituent; *1 and *2 represent the bonding part with the carbonyl group, respectively, and *1 and *2 can also be reversed.

8. The metal-containing film-forming compound according to claim 1, wherein The terminal structure of the polymer having the repeating unit of the general formula (P-1) is the following general formula (T-1), or the terminal structure of the polymer having the repeating unit of the general formula (P-2) is the following general formula (T-2); In the general formulae (T-1) to (T-2), R1, R2, R3, W1, W2, s1, s2 and s3 are the same as those in the general formulae (P-1) to (P-2).

9. The metal-containing film-forming compound according to claim 1, wherein The terminal structure of the polymer having the repeating unit of the general formula (P-1) or (P-2) is *-OC(=O)R, where R is a monovalent organic group and * represents a bonding portion with a Sn atom in the polymer.

10. The metal-containing film-forming compound according to claim 9, wherein In the terminal structure *-OC(=O)R, R is any one of the groups represented by the following general formulae (A-1) to (A-4), the following general formula (3), and the following general formula (4); In the general formulas (A-1) to (A-4), Y A1 , Y A2 may be the same as or different from each other, and are a substituted or unsubstituted saturated divalent organic group having 1 to 23 carbon atoms or an unsaturated divalent organic group having 2 to 23 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkylene group having 7 to 31 carbon atoms; R A is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, R A1 It is an organic group represented by the following general formula (2), in which the protective group is released by the action of either or both of acid and heat to generate one or more hydroxyl groups or carboxyl groups, and * represents a bonding portion with a carbonyl group; In the general formula (2), R A2 is an organic group whose protective group is released by the action of either acid or heat or both, and * indicates A1 or Y A2 The bonding portion; In the general formula (3), X is a divalent organic group having 1 to 31 carbon atoms, B is the following general formula (B), and * represents a bonding portion with a carbonyl group; B=*-Y B -R B (B) In the general formula (B), Y B is a substituted or unsubstituted saturated or unsaturated divalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted divalent arylene group having 6 to 30 carbon atoms, or a substituted or unsubstituted divalent arylalkylene group having 7 to 31 carbon atoms, R B is a hydroxyl group or any one of the structures represented by the following general formulas (B-1) to (B-3); In the general formulas (B-1) to (B-3), R B1 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents B The bonding portion; In the general formula (4), X is a divalent organic group having 1 to 31 carbon atoms, C is any one of the groups represented by the following general formulae (C-1) to (C-4), and * represents a bond to a carbonyl group; In the general formulas (C-1) and (C-3), R C1 is a hydrogen atom or a methyl group, and they may be the same or different from each other in the same formula; in (C-3) and (C-4), R C2 It is a hydrogen atom, or a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms; * represents a bonding portion to the carbonyl group.

11. The metal-containing film-forming compound according to claim 10, wherein In the general formulas (A-1) to (A-4), Y A1 , X in the general formula (3) or X in the general formula (4) is an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

12. The metal-containing compound for film formation according to claim 10, wherein In the general formulas (A-1) to (A-4), Y A1 , X in the general formula (3) or X in the general formula (4) is a group represented by the following general formula (1); In the general formula (1), R a , R b and R c is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, R a With R b It can also bond to form a cyclic substituent; *1 and *2 represent the bonding part with the carbonyl group, respectively, and *1 and *2 can also be reversed.

13. A metal-containing film-forming composition which functions as a resist underlayer film material used in semiconductor manufacturing, characterized in that contain: (a) the metal-containing film-forming compound according to any one of claims 1 to 12, and (b) Organic solvents.

14. The metal-containing film-forming composition according to claim 13, wherein The composition is a composition for forming a metal-containing film that can be used as a resist underlayer film used in a multilayer resist method, and further contains one or more of (c) a crosslinking agent, (d) a surfactant, (e) a fluidity promoter, and (f) an acid generator.

15. The metal-containing film-forming composition according to claim 13, wherein The (b) organic solvent is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher.

16. A method for forming a pattern on a processed substrate. The method is characterized by having the following steps: (I-1) Coating on the substrate to be processed The metal-containing film-forming composition according to claim 13 is then subjected to heat treatment to form a metal-containing film, (I-2) forming a resist upper layer film on the metal-containing film using a photoresist material, (I-3) after exposing the resist upper layer film to pattern exposure, developing with a developer to form a pattern on the resist upper layer film, (I-4) using the patterned resist upper layer film as a mask and transferring the pattern to the metal-containing film by dry etching, and (I-5) The substrate to be processed is processed using the patterned metal-containing film as a mask to form a pattern on the substrate to be processed.

17. A method for forming a pattern on a processed substrate. The method is characterized by having the following steps: (II-1) Coating on the substrate to be processed The metal-containing film-forming composition according to claim 13 is then subjected to heat treatment to form a metal-containing film, (II-2) forming a resist intermediate film on the metal-containing film, (II-3) forming a resist upper film on the resist intermediate film using a photoresist material, (II-4) after exposing the resist upper layer film to pattern exposure, developing 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 to the resist intermediate film by dry etching, (II-6) using the resist intermediate film having the transferred pattern as a mask, and transferring the pattern to the metal-containing film by dry etching, and (II-7) The substrate to be processed is processed using the patterned metal-containing film as a mask to form a pattern on the substrate to be processed.

18. A method for forming a pattern on a processed substrate. The method is characterized by having the following steps: (III-1) Coating on the substrate to be processed The metal-containing film-forming composition according to claim 13 is then subjected to heat treatment to form a metal-containing film, (III-2) forming an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a 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) forming a resist upper layer film on the organic thin film using a photoresist material, (III-5) after exposing the resist upper layer film to pattern exposure, developing 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 thin film and the inorganic hard mask intermediate film by dry etching, (III-7) using the inorganic hard mask intermediate film having the transferred pattern as a mask, and transferring the pattern to the metal-containing film by dry etching, and (III-8) The substrate to be processed is processed using the patterned metal-containing film as a mask to form a pattern on the substrate to be processed.

19. A method for forming a pattern on a processed substrate. The method is characterized by having the following steps: (IV-1) forming a resist underlayer film on a substrate to be processed, (IV-2) coating on the resist underlayer film The metal-containing film-forming composition according to claim 13 is then subjected to heat treatment to form a metal-containing film, (IV-3) forming a resist upper layer film on the metal-containing film using a photoresist material, or forming a non-conductive film on the metal-containing film by spin coating, and forming a resist upper layer film thereon using a photoresist material, (IV-4) after exposing the resist upper layer film to pattern exposure, developing with a developer to form a pattern on the resist upper layer film, (IV-5) using the patterned resist upper layer film as a mask, and transferring the pattern to the metal-containing film, or the organic composite film and the metal-containing film by dry etching, (IV-6) using the metal-containing film having the transferred pattern as a mask, and transferring the pattern to the resist underlayer film by dry etching, and (IV-7) The substrate to be processed is processed using the patterned resist underlayer film as a mask to form a pattern on the substrate to be processed.

20. A method for forming a pattern on a processed substrate. The method is characterized by having the following steps: (V-1) forming a resist underlayer film on a substrate to be processed, (V-2) forming a resist intermediate film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film and an organic thin film on the resist underlayer film, (V-3) forming a resist upper layer film using a photoresist material on the resist intermediate film or on a combination of an inorganic hard mask intermediate film and an organic thin film, (V-4) after pattern exposure of the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film, (V-5) using the patterned resist upper film as a mask, and transferring the pattern to the resist intermediate film, or the organic thin film and the inorganic hard mask intermediate film by dry etching, (V-6) using the resist intermediate film or inorganic hard mask intermediate film having the transferred pattern as a mask, and transferring the pattern to the resist underlayer film by dry etching, (V-7) coating the patterned resist underlayer film The metal-containing film-forming composition according to claim 13 is then heat-treated to coat the metal-containing film and fill the space between the resist underlayer film patterns with the metal-containing film, (V-8) etching back the metal-containing film covering the resist underlayer film having the pattern by chemical stripping or dry etching to expose the top surface of the resist underlayer film having the pattern, (V-9) removing the resist intermediate film or the hard mask intermediate film remaining on the top surface of the resist lower layer film by dry etching, (V-10) removing the exposed surface of the resist underlayer film having the pattern formed thereon by dry etching, and forming a reverse pattern of the original pattern on the metal-containing film, and (V-11) The metal-containing film having the reverse pattern formed thereon is used as a mask to process the substrate to be processed, thereby forming a reverse pattern on the substrate to be processed. 21 . The pattern forming method according to claim 18 , wherein the inorganic hard mask intermediate film is formed by a CVD method or an ALD method. 22 . The pattern forming method according to claim 20 , wherein the inorganic hard mask intermediate film is formed by a CVD method or an ALD method.

Images