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. Provided are: a metal compound which has excellent dry etching resistance and also has a high degree of film-forming properties and a high tin content; a metal-containing film-forming composition which uses the metal compound; and a method for forming a pattern on a resist underlayer film material using the metal compound. A metal-containing film-forming compound characterized by being represented by general formula (M) (in general formula (M), T independently represents general formula (T-1) or (T-2), P independently represents * OCOR (* represents a bonding part with a Sn atom, and R represents a monovalent organic group), and Q independently represents a C1-20 alkyl group, a cycloalkyl group, an aliphatic unsaturated hydrocarbon group, an alkoxy group, a C6-30 aryl group, a C7-31 arylalkyl group, or a halogen atom. N1, n2 and n3 are integers which meet the conditions that n1 is greater than or equal to 1, n2 is greater than or equal to 0, n3 is greater than or equal to 1, and n1 + n2 + n3 = 4. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to a fine patterning method using a multilayer resist method in a semiconductor device manufacturing process, which can use a metal-containing film-forming compound, a metal-containing film-forming composition using 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 progressed rapidly. As the most advanced miniaturization technology, mass production of devices after the 45 nm node uses ArF immersion lithography. Also, combined with ArF immersion exposure, double exposure (double patterning) processing has been put into practical use in the generation after the 28 nm node, and the formation of narrow pitch patterns beyond the optical limit has been achieved.

[0003] Also, for device manufacturing after the 20 nm node, multiple exposure (multi-patterning) processing, which repeats exposure and etching three or more times to form narrower pitch patterns, is being studied. However, because the number of steps increases in multiple exposure processing, the manufacturing period becomes longer, the frequency of defect occurrence increases, productivity decreases, and a significant increase in cost is encountered.

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

[0005] On the other hand, for EUV lithography, in order to compensate for the insufficient output of the light source, high sensitivity of the photoresist material is strongly required. However, an increase in shot noise associated with high sensitivity is related to an increase in the edge roughness (LER, LWR) of line patterns. One of the important issues in EUV lithography is to achieve both high sensitivity and low edge roughness.

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

[0007] For example, the use of photoresist materials added with metal salts and organometallic complexes described in Patent Documents 1 and 2, and non-chemically amplified photoresist materials using metal oxide nanoparticles described in Patent Documents 3 and 4 have been explored.

[0008] Among them, tin-containing molecules have been actively studied due to their excellent absorption of electron beams and extreme ultraviolet light. In the case of an organotin polymer, which is one of them, the alkyl ligand dissociates due to light absorption or secondary electrons generated thereby, and negative tone patterning that cannot be removed by an organic developing solution can be achieved by crosslinking with oxygen-containing bonds of surrounding chains. Such an organotin polymer can maintain resolution, line edge roughness, and improve sensitivity, but has not yet reached the commercialization level (Patent Document 5). In addition, there are still many problems such as insufficient storage stability against changes in resist sensitivity.

[0009] Regarding the above problems, some people have also explored the development of materials containing metal elements such as titanium, hafnium, zirconium, and tin for use as an anti-reflective coating underlayer film. It is possible to provide performance improvements such as an increase in exposure sensitivity, which is a problem for metal-containing photoresist materials, and suppression of sensitivity changes in a storage environment, and an anti-reflective coating underlayer film with excellent dry etching resistance by containing the above metal elements. Patent Document 7 reports that a material using a Ti compound shows excellent dry etching resistance against CHF3 / CF4-based gases and CO2 / N2-based gases.

[0010] On the other hand, problems with metal compounds when used as an anti-reflective coating underlayer film include, for example, film-forming properties and filling properties. For example, the compounds used in a photoresist as in Patent Document 6 do not mention heat resistance, but since these compounds are not used for high-temperature baking, their heat resistance may be insufficient, resulting in filling and film-forming defects. Also, although film-forming properties and filling properties are not mentioned in Patent Document 7, metal oxide compounds generally exhibit large thermal shrinkage during baking and induce significant deterioration of filling properties after high-temperature baking. Therefore, there are concerns about insufficient heat resistance characteristics such as film-forming properties and filling characteristics required for an anti-reflective coating underlayer film material. 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 carried out is a low temperature of 150 °C, and there are concerns that it is not ideal for an anti-reflective coating underlayer film that requires heat resistance (for example, characteristics of heat treatment sometimes carried out after the formation of an anti-reflective coating underlayer film). Patent Document 9 provides an anti-reflective coating 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, but since it is a mixed composition of an inorganic metal compound and an organic polymer, there are concerns about 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 for International Application No. 2021-162865

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

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

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

[0021] [Patent Document 9] Japanese Patent Publication for International Application No. 2022-521531 Summary of the Invention

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

[0023] The present invention has been made in view of the above circumstances, and an object thereof is to provide a compound for forming a metal-containing film that has excellent dry etching resistance compared to known organic underlayer film materials, and that also takes into account a high degree of film formability and a 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 represented by the following general formula (M).

[0026] [Chemical Formula 1]

[0027]

[0028] In the above general formula (M), T is independently the following general formula (T-1) or (T-2), P is independently *OCOR (* represents the bonding part with the Sn atom, and R represents a monovalent organic group), and Q is independently 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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, a halogen atom, or an alkoxy group having 1 to 20 carbon atoms. Also, n1, n2, and n3 are integers satisfying n1≥1, n2≥0, n3≥1 and n1 + n2 + n3 = 4. When n1≥2, Ts can be the same or different, when n2 = 2, Ps can be the same or different, and when n3≥2, Qs can be the same or different.

[0029] [Chemical formula 2]

[0030]

[0031] In the above general formulas (T-1) and (T-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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * is the bonding part with the Sn atom in the above general formula (M). W1 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms (including aromatic ring groups), and the above hydrocarbon group contains oxygen atoms, nitrogen atoms, and sulfur atoms as heteroatoms, and can also form ether bonds, carbonyl groups, ester groups, amide groups, and can also form a heterocyclic structure with the above 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 m is an integer of 0 to 1. W2 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms (including aromatic ring groups), and the above hydrocarbon group contains oxygen atoms, nitrogen atoms, and sulfur atoms as heteroatoms, and can also form ether bonds, carbonyl groups, ester groups, amide groups, and can also form a heterocyclic structure with the above 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 bonded thereto forms a carbonyl group. W2 and R3 can also bond to each other and form a ring structure.

[0032] In the case of such a tin-containing compound, since the radical cleavage of the Sn-alkyl bond generates radicals, a crosslinking reaction is caused by these radicals. Further, since the units (T) having catechol or diol are bonded to tin, multiple tin atoms can be introduced into one molecule, and thus the tin content can be increased. Furthermore, in the above general formula (M), when n2 is 1, n1 is 2, and T is different, the symmetry of the molecule is broken, and thus the solvent solubility can be improved. Therefore, the compound of the present invention has excellent solvent solubility and is suitable as a composition for forming a metal film, and can form a film having a high tin content when used as an underlayer film for a resist.

[0033] In the above compound, (i) in the above general formula (T-1), W1 is preferably any of a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms (including an aromatic ring group) which may contain a hydroxyl group or an amino group (the above 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 a group represented by the following general formula (W1-1) to (W1-4).

[0034] [Chemical formula 3]

[0035]

[0036] In the above general formula (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 group, and #2 represents the bonding part with the benzene ring.

[0037] Further, in the above compound, (ii) in the above general formula (T-2), W2 is preferably any of a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms (including an aromatic ring group) which may contain a hydroxyl group or an amino group, a cyclic hydrocarbon group formed by bonding with R3 (the above 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 a group represented by the following general formula (W2-1) to (W2-4).

[0038] [Chemical formula 4]

[0039]

[0040] In the above general formula (W2-1) to (W2-4), R W is a divalent organic group having 1 to 23 carbon atoms, and #1 and #2 each represent the bonding part with the ester group and the carbon atom.

[0041] If W1 in the above general formula (T-1) and / or W2 in (T-2) has the above structure, the proportion of the organic group can be suppressed, and the tin content can be increased.

[0042] Further, in the general formulas (W1-1) to (W1-4) of the above (i), and / or R in the general formulas (W2-1) to (W2-4) of the above (ii) W is preferably an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

[0043] R in the general formulas (W1-1) to (W1-4) and (W2-1) to (W2-4) above W If it is an unsaturated hydrocarbon group having 2 to 23 carbon atoms, the thermosetting property of the above compound can be further improved.

[0044] 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).

[0045] [Chemical formula 5]

[0046]

[0047] 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 each represent a bonding portion to the carbonyl group, and *1 and *2 may also be interchanged.

[0048] In the general formulas (W1-1) to (W1-4) and (W2-1) to (W2-4) above, R W If it is a group represented by the above general formula (1), the thermosetting property and the high tin content can be balanced, and when it is used in a metal-containing film-forming composition, it can provide a resist underlayer film material having better film-forming properties and a high tin content.

[0049] Further, in the aforementioned general formula (M), it is preferable that n2 is 1, and R of *OCOR of P 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).

[0050] [Chemical formula 6]

[0051]

[0052] In the aforementioned general formulas (A-1) to (A-4), Y A1 , Y A2They may be the same as or different from each other, and are a substituted or unsubstituted divalent organic group with 1 to 23 carbon atoms that is saturated or an unsaturated divalent organic group with 2 to 23 carbon atoms, a substituted or unsubstituted arylene group with 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkylene group with 7 to 31 carbon atoms. R A is a hydrogen atom, a substituted or unsubstituted monovalent organic group with 1 to 20 carbon atoms that is saturated or an unsaturated monovalent organic group with 2 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group with 7 to 31 carbon atoms, 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.

[0053] [Chemical formula 7]

[0054]

[0055] 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 's bonding portion.

[0056] [Chemical formula 8]

[0057]

[0058] In the aforementioned general formula (3), X is a divalent organic group with 1 to 31 carbon atoms, B is the following general formula (B), and * represents the bonding portion to the carbonyl group.

[0059] [Chemical formula 9]

[0060] B = *-Y B -R B (B)

[0061] In the aforementioned general formula (B), Y B is a substituted or unsubstituted divalent organic group with 1 to 20 carbon atoms that is saturated or an unsaturated divalent organic group with 2 to 20 carbon atoms, a substituted or unsubstituted divalent arylene group with 6 to 30 carbon atoms, or a substituted or unsubstituted divalent arylalkylene group with 7 to 31 carbon atoms, R B is a hydroxyl group or any of the structures represented by the following general formulas (B-1) to (B-3).

[0062] [Chemical formula 10]

[0063]

[0064] In the aforementioned general formulas (B-1) to (B-3), R B1 is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents the bonding portion to YB bonding part

[0065] [Chemical formula 11]

[0066]

[0067] In the above 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 formulas (C-1) to (C-4), and * represents the bonding part with the carbonyl group.

[0068] [Chemical formula 12]

[0069]

[0070] In the above 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 is a hydrogen atom or a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms (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. * represents the bonding part with the carbonyl group.

[0071] When R has the structure represented by the above general formulas (A-1) to (A-4), the structure contains an organic group in which the protecting group is detached due to the action of either a bulky acid, heat, or both, so the solvent solubility of the compound can be improved. Furthermore, when it is used in a metal-containing film-forming composition, the protecting group is detached during baking to generate a hydroxyl group and a carboxyl group. The OH and the α-hydrogen of the carboxylic acid generated thereby are likely to react with the free radicals generated by the cleavage of the tin-carbon bond during baking and cause a crosslinking reaction. Therefore, the compound of the present invention has excellent thermosetting properties and can suppress the volume shrinkage that induces deterioration of film-forming properties and filling properties. Furthermore, it can also provide a resist underlayer film material having excellent film-forming properties and filling characteristics even during high-temperature baking.

[0072] Also, when R has the structure represented by the above general formula (3), it has a hydroxyl group at the end or a crosslinking group having any one of the structures represented by the above general formulas (B-1) to (B-3). Therefore, when they are used in a metal-containing film-forming composition, during baking, not only the crosslinking reaction between free radicals generated by the cleavage of the tin-carbon bond occurs, but also the reaction between free radicals and crosslinking groups and the further crosslinking reaction between crosslinking groups occur. Therefore, they have excellent thermosetting properties and can suppress the volume shrinkage that induces deterioration of film-forming properties and filling properties, and can provide a resist underlayer film material having excellent film-forming properties and filling characteristics even after high-temperature baking.

[0073] Moreover, when R has the structure represented by the above general formula (4), since any structure represented by (C-1) to (C-4) is contained at the terminal, the crosslinking group density of the foregoing 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 excellent in film-forming property and filling property even after high-temperature baking can be provided.

[0074] 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 preferably an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

[0075] Y in the above general formulas (A-1) to (A-4) A1 , X in the above general formula (3), or if X in the above general formula (4) is an unsaturated hydrocarbon group having 2 to 23 carbon atoms, the thermosetting property of the above metal-containing film-forming compound can be further improved.

[0076] In this case, 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) may be a group represented by the following general formula (1).

[0077] [Chemical formula 13]

[0078]

[0079] In the foregoing 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 each represent a bonding portion to a carbonyl group, and *1 and *2 may also be interchanged.

[0080] Y in the above general formulas (A-1) to (A-4) A1 , X in the above general formula (3), or if X in the above general formula (4) is a group represented by the following general formula (1), the thermosetting property can be improved, and when they are used in a metal-containing film-forming composition, a resist underlayer film material showing better film-forming property can be provided.

[0081] Furthermore, the present invention can provide a metal-containing film-forming composition, which is a metal-containing film-forming composition acting as a resist underlayer film material used in semiconductor manufacturing, and is characterized by containing (a) the above metal-containing film-forming compound and (b) an organic solvent.

[0082] If it is a composition for forming a metal-containing film, since it contains an organotin compound having excellent solvent solubility and heat resistance, it can provide a resist underlayer film material having better dry etching resistance than known organic underlayer film materials and achieving a high degree of film formability.

[0083] The above composition is a composition for forming a metal-containing film that can be used as a resist underlayer film in a 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.

[0084] Furthermore, it is preferable that the above (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.

[0085] By adding a high-boiling solvent to the above metal-containing film-forming compound to impart thermal fluidity, the planarization characteristics of the composition for forming a resist underlayer film can be further improved.

[0086] 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 the following features:

[0087] (I-1) After coating the composition for forming a metal-containing film of the present invention on the substrate to be processed, a metal-containing film is formed by heat treatment.

[0088] (I-2) A resist upper layer film is formed on the aforementioned metal-containing film using a photoresist material.

[0089] (I-3) After pattern exposure of the aforementioned resist upper layer film, it is developed with a developer to form a pattern on the aforementioned resist upper layer film.

[0090] (I-4) Using the aforementioned patterned resist upper layer film as a mask, a pattern is transferred to the aforementioned metal-containing film by dry etching, and

[0091] (I-5) Using the aforementioned patterned metal-containing film as a mask, the aforementioned substrate to be processed is processed to form a pattern on the aforementioned substrate to be processed.

[0092] By using the pattern formation method performed by the above two-layer resist treatment, a fine pattern can be formed on the object to be processed (substrate to be processed).

[0093] 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 the following steps:

[0094] (II-1) After coating the composition for forming a metal-containing film of the present invention on the substrate to be processed, a metal-containing film is formed by heat treatment.

[0095] (II-2) Form a resist intermediate film on the aforementioned metal-containing film.

[0096] (II-3) Form a resist upper layer film on the aforementioned resist intermediate film using a photoresist material.

[0097] (II-4) After pattern exposure of the aforementioned resist upper layer film, develop it with a developer to form a pattern on the aforementioned resist upper layer film.

[0098] (II-5) Use the aforementioned patterned resist upper layer film as a mask to transfer the pattern to the aforementioned resist intermediate film by dry etching.

[0099] (II-6) Use the aforementioned resist intermediate film with the transferred pattern as a mask to transfer the pattern to the aforementioned metal-containing film by dry etching, and

[0100] (II-7) Use the aforementioned patterned metal-containing film as a mask to process the aforementioned substrate to be processed and form a pattern on the aforementioned substrate to be processed.

[0101] With the pattern formation method using the above three-layer resist treatment, fine patterns can be formed with high precision on the object to be processed.

[0102] Further, the present invention provides a pattern formation method, which is a method for forming a pattern on a substrate to be processed, characterized by having the following steps:

[0103] (III-1) After coating the composition for forming a metal-containing film of the present invention on the substrate to be processed, form a metal-containing film by heat treatment.

[0104] (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.

[0105] (III-3) Form an organic thin film on the aforementioned inorganic hard mask intermediate film.

[0106] (III-4) Form a resist upper layer film on the aforementioned organic thin film using a photoresist material.

[0107] (III-5) After pattern exposure of the aforementioned resist upper layer film, develop it with a developer to form a pattern on the aforementioned resist upper layer film.

[0108] (III-6) Use the aforementioned patterned resist upper layer film as a mask to transfer the pattern to the aforementioned organic thin film and the aforementioned inorganic hard mask intermediate film by dry etching.

[0109] (III-7) Use the aforementioned inorganic hard mask intermediate film with the transferred pattern as a mask to transfer the pattern to the aforementioned metal-containing film by dry etching, and

[0110] (III-8) Using the metal-containing film with the formed pattern as a mask, processing the substrate to be processed to form a pattern on the substrate to be processed.

[0111] With the pattern formation method carried out by the above four-layer resist treatment, fine patterns can be formed on the object to be processed with high precision.

[0112] In this case, it is preferable to form the above inorganic hard mask intermediate film by CVD method or ALD method.

[0113] If the above inorganic hard mask is formed by CVD method or ALD method, fine patterns can be formed on the object to be processed with high precision.

[0114] Further, 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:

[0115] (IV-1) Forming a lower resist film on the substrate to be processed,

[0116] (IV-2) After coating the composition for forming a metal-containing film of the present invention on the above lower resist film, forming a metal-containing film by heat treatment,

[0117] (IV-3) Forming an upper resist film on the above metal-containing film using a photoresist material, or spin-coating an organic conformal film on the above metal-containing film, and forming an upper resist film using a photoresist material thereon,

[0118] (IV-4) After pattern exposure of the above upper resist film, developing with a developer to form a pattern on the above upper resist film,

[0119] (IV-5) Using the upper resist film with the formed pattern as a mask, transferring the pattern to the above metal-containing film, or the above organic conformal film and the above metal-containing film by dry etching,

[0120] (IV-6) Using the metal-containing film with the transferred pattern as a mask, transferring the pattern to the above lower resist film by dry etching, and

[0121] (IV-7) Using the lower resist film with the formed pattern as a mask, processing the substrate to be processed to form a pattern on the substrate to be processed.

[0122] With the pattern formation method carried out by the above multi-layer resist treatment, fine patterns can be formed on the object to be processed with high precision.

[0123] Further, 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 including the following steps:

[0124] (V-1) Form a lower resist film on the substrate to be processed.

[0125] (V-2) Form a resist intermediate film on the aforementioned 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.

[0126] (V-3) Using a photoresist material, form an upper resist film on the aforementioned resist intermediate film, or a combination of an inorganic hard mask intermediate film and an organic thin film.

[0127] (V-4) After pattern exposure of the aforementioned upper resist film, develop it with a developer to form a pattern on the aforementioned upper resist film.

[0128] (V-5) Using the aforementioned patterned upper resist film as a mask, transfer the pattern to the aforementioned resist intermediate film, or the aforementioned organic thin film and the aforementioned inorganic hard mask intermediate film by dry etching.

[0129] (V-6) Using the aforementioned patterned resist intermediate film, or the inorganic hard mask intermediate film as a mask, transfer the pattern to the aforementioned lower resist film by dry etching.

[0130] (V-7) After coating the composition for forming a metal-containing film of the present invention on the aforementioned patterned lower resist film, coat the metal-containing film by heat treatment, and fill the spaces between the patterns of the aforementioned lower resist film with the aforementioned metal-containing film.

[0131] (V-8) Chemically strip or dry etch back the metal-containing film coated on the aforementioned patterned lower resist film to expose the top surface of the patterned lower resist film.

[0132] (V-9) Remove the remaining resist intermediate film, or the hard mask intermediate film on the top surface of the aforementioned lower resist film by dry etching.

[0133] (V-10) Remove the patterned lower resist film with the exposed surface by dry etching to form an inverted pattern of the original pattern on the metal-containing film.

[0134] (V-11) Using the aforementioned inverted-patterned metal-containing film as a mask, process the aforementioned substrate to be processed to form an inverted pattern on the aforementioned substrate to be processed.

[0135] The pattern formation method using the above inversion process can form a fine pattern with higher precision on the object to be processed.

[0136] In this case, it is also preferable to form the above inorganic hard mask intermediate film by CVD method or ALD method.

[0137] When the above inorganic hard mask is formed by CVD method or ALD method, a fine pattern can be formed on the workpiece with higher precision.

[0138] [Effects of the Invention]

[0139] As described above, the metal-containing film-forming compound of the present invention is a compound represented by the above general formula (M). Therefore, during baking, radicals are generated due to the radical cleavage of the Sn-alkyl bond, and a crosslinking reaction is caused by using these radicals. Moreover, since the catechol and diol units have tin bonds, multiple tin atoms can be introduced into one molecule, so the tin content rate can be increased. Furthermore, in the above general formula (M), when n2 is 1, n1 is 2 and T is different, the symmetry of the molecule is broken, so the solvent solubility can be improved. Therefore, the composition using the compound of the present invention has excellent solvent solubility and can provide a resist underlayer film material with a high tin content rate.

[0140] In particular, even in the fine patterning process using the multilayer resist method in the semiconductor device manufacturing process, on a workpiece substrate such as a dense portion of a fine pattern structure with a high aspect ratio represented by a DRAM memory where miniaturization progresses and there are parts with difficulties in filling / planarization, it can be filled without defects such as pores and peeling. Also, compared with known coating-type organic resist underlayer film materials, it has better dry etching resistance. Therefore, a fine pattern can be formed on the workpiece with higher precision compared to the organic resist underlayer film.

[0141] Moreover, the metal-containing film-forming composition containing the metal-containing film-forming compound of the present invention contains tin atoms with a large EUV light absorption. Therefore, there is a sensitizing effect obtained from secondary electrons generated from it during exposure. Furthermore, since the atomic weight of tin atoms is large, the effect of suppressing the acid diffusion from the upper resist to the resist underlayer film is high, and the upper resist film has the characteristic of being able to maintain the originally possessed LWR performance and being highly sensitive. BRIEF DESCRIPTION OF THE DRAWINGS

[0142] Figure 1 (A) - (F) show an explanatory diagram of an example of the pattern formation method of the present invention (3-layer resist process).

[0143] Figure 2 (G) - (P) show an explanatory diagram of an example of the tone inversion type pattern formation method of the present invention (inversion of the SOC pattern in the 3-layer resist process).

[0144] Figure 3 (Q) - (S) show an explanatory diagram of the filling property evaluation method. DETAILED DESCRIPTION OF THE INVENTION

[0145] As described above, there is a need to develop a metal-containing film-forming composition with excellent film-forming properties that can be used to transfer a resist pattern onto an underlying resist film of a substrate to be processed with higher precision in fine patterning using a multi-layer resist method, and a metal-containing film-forming compound useful for the composition.

[0146] The inventors of the present application focused on organotin compounds that could be expected to be active in the EUV exposure generation and made efforts to investigate. As described above, tin atoms with a large EUV light absorption have a sensitizing effect especially brought about by secondary electrons generated during exposure, and have the characteristics of being able to maintain the LWR performance originally possessed by the upper resist film and being able to achieve high sensitivity. On the other hand, the organotin compounds investigated for the upper resist film lack heat resistance and cause severe volume shrinkage during baking, so it is difficult to form a uniform film and fill the height difference of the substrate to be processed during high-temperature baking. The inventors of the present application considered that if an organic molecule having a diol structure (including catechol) and a carboxylate group in the molecule reacts with a tin compound, multiple tin atoms can be introduced into the molecule and the molecular weight can be increased. There is a high possibility that even if the bonds are broken during baking, a sufficient molecular weight can still be maintained, sublimates can be suppressed, heat resistance can be improved, and excellent film-forming properties can be exhibited. And since multiple tin atoms can be introduced into one molecule, not only can the heat resistance be improved but also the tin content rate can be increased, and it is considered that it will become a metal-containing film-forming composition showing excellent etching resistance.

[0147] The inventors of the present application made further efforts to investigate and found that if the metal-containing film-forming compound represented by the above general formula (M) is used, the film-forming properties are excellent, and furthermore, the tin content rate can be increased, so it will become a metal-containing film-forming compound with excellent etching resistance, and thus the present invention was completed.

[0148] That is, the present invention is a metal-containing film-forming compound, which is a metal-containing film-forming compound that can be used as a metal-containing film-forming composition serving as an underlying resist film material used in semiconductor manufacturing, and is characterized in that the aforementioned compound is represented by the following general formula (M).

[0149] [Chemical formula 14]

[0150]

[0151] In the general formula (M) described above, T is independently the following general formula (T-1) or (T-2), P is independently *OCOR (* represents the bonding part with the Sn atom, and R represents a monovalent organic group), and Q is independently 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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, a halogen atom, or an alkoxy group having 1 to 20 carbon atoms. Also, n1, n2, and n3 are integers satisfying n1≥1, n2≥0, n3≥1 and n1 + n2 + n3 = 4. When n1≥2, the Ts may be the same or different, when n2 = 2, the Ps may be the same or different, and when n3≥2, the Qs may be the same or different from each other.

[0152] [Chemical Formula 15]

[0153]

[0154] In the general formulas (T-1) and (T-2) described 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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * is the bonding part with the Sn atom in the general formula (M) described above. W1 is a substituted or unsubstituted linear, branched, or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms (including an aromatic ring group), and the hydrocarbon group contains oxygen, nitrogen, or sulfur atoms as heteroatoms, and may form an ether bond, a carbonyl group, an ester group, an amide group, or may 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 m is an integer of 0 to 1. W2 is a substituted or unsubstituted linear, branched, or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms (including an aromatic ring group), and the hydrocarbon group contains oxygen, nitrogen, or sulfur atoms as heteroatoms, and may form an ether bond, a carbonyl group, an ester group, an amide group, or may 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 forms a carbonyl group. W2 and R3 may also be bonded to each other to form a ring structure.

[0155] The following is a detailed description of the present invention, but the present invention is not limited thereto. Also, catechol (1,2-benzenediol) is also included in diols, but in this specification, a compound having a 1,2-benzenediol structure is referred to as catechol, and diols other than this are sometimes simply referred to as "diols".

[0156] <Compound for forming a metal-containing film>

[0157] The metal-containing film-forming compound of the present invention is a metal-containing film-forming compound characterized by being represented by the following general formula (M). The aforementioned compound can be used as a metal-containing film-forming composition that can function as an underlayer film material for resists used in semiconductor manufacturing.

[0158] [Chemical formula 16]

[0159]

[0160] In the aforementioned general formula (M), T is independently the following general formula (T-1) or (T-2), P is independently *OCOR (* represents the bonding part to the Sn atom, and R represents a monovalent organic group), and Q is independently 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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, a halogen atom, or an alkoxy group having 1 to 20 carbon atoms. Also, n1, n2, and n3 are integers that satisfy n1≥1, n2≥0, n3≥1 and n1 + n2 + n3 = 4. When n1≥2, Ts can be the same or different from each other. When n2 = 2, Ps can be the same or different from each other. When n3≥2, Qs can be the same or different from each other.

[0161] [Chemical formula 17]

[0162]

[0163] In the aforementioned general formulas (T-1) and (T-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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * is a bonding part with the Sn atom in the aforementioned general formula (M). W1 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms (including an aromatic ring group, and the aforementioned hydrocarbon group contains oxygen atom, nitrogen atom, sulfur atom as heteroatoms, and may 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 m is an integer of 0 to 1. W2 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 40 carbon atoms (including an aromatic ring group), and the aforementioned hydrocarbon group contains oxygen atom, nitrogen atom, sulfur atom as heteroatoms, and may 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. 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 bonded thereto forms a carbonyl group, and W2 and R3 may also bond to each other to form a ring structure.

[0164] In the above general formula (M), P is independently *OCOR (* represents a bonding part with the Sn atom, and R represents a monovalent organic group). R is, for example, a linear hydrocarbon group such as methyl, ethyl, n-butyl, a branched hydrocarbon group such as isopropyl, tert-butyl, a cyclic hydrocarbon group such as cyclohexane, cyclopropane, other ether groups, ester groups, amide groups, aryl groups, arylalkyl groups, groups containing unsaturated bonds, etc. They may be substituted or unsubstituted, and there is no special limitation if it is a group derived from a monovalent carboxylic acid. From the viewpoint of crosslinkability, a structure containing an unsaturated bond, or a hydroxyl group, or a structure in which a protecting group is removed by heat or acid to generate a hydroxyl group or a carboxyl group is preferred.

[0165] Also, hereinafter, in order to represent a primary alkyl group by the alkyl name, n may be described, and in order to represent a secondary alkyl group and a tertiary alkyl group, they may be described as s, t, or sec-, tert-, respectively.

[0166] In the above general formula (M), Q is independently 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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, a halogen atom, or an alkoxy group having 1 to 20 carbon atoms. From the perspective of raw material availability, n-butyl, t-butyl, n-octyl, benzyl, halogen atoms, and alkoxy groups are preferred, and n-butyl is more preferred. Also, considering the ease of occurrence of radical cleavage of the Sn-alkyl bond, t-butyl and benzyl are also ideal.

[0167] In the above general formula (M), T is independently the above general formula (T-1) or (T-2). In the general formulas (T-1) to (T-2), R1 is preferably 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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, or a combination thereof. From the perspective of raw material availability, n-butyl, t-butyl, n-octyl, and benzyl are preferred, and n-butyl is more preferred. Also, considering the ease of occurrence of radical cleavage of the Sn-alkyl bond, t-butyl and benzyl are also ideal.

[0168] In the above general formula (M), n1, n2, and n3 are integers that satisfy n1≥1, n2≥0, n3≥1, and n1 + n2 + n3 = 4. When n1≥2, the Ts can be the same or different, when n2 = 2, the Ps can be the same or different, and when n3≥2, the Qs can be the same or different. From the perspective of increasing the tin content, n1 = 3 and n3 = 1 are preferred. From the perspective of disrupting molecular symmetry and improving solubility, n1 = 2, n2 = 1, and n3 = 1 are preferred.

[0169] In the above general formula (T-1), W1 is a substituted or unsubstituted linear, branched, or cyclic saturated or unsaturated hydrocarbon group (including aromatic groups) having 1 to 40 carbon atoms. The aforementioned hydrocarbon group contains oxygen atoms, nitrogen atoms, and sulfur atoms as heteroatoms, and can also form ether bonds, carbonyl groups, ester groups, and amide groups. It can also form a heterocyclic structure by spacing the aforementioned heteroatoms like an intervening amide group or ester group. However, from the perspectives of heat resistance and increasing the Sn content, W1 is preferably a linear, branched, or cyclic saturated or unsaturated hydrocarbon group having 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 can also form ether bonds, carbonyl groups, and ester groups). s1 is an integer from 0 to 1. From the perspective of increasing the tin content, s1 is preferably 0. From the perspectives of thermal fluidity and landfillability, it is better to contain an organic chain, so s1 is preferably 1. Also, when s1 = 0, it means that the carbonyl group is bonded by a single bond.

[0170] More specifically, W1 is preferably 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 as heteroatoms and may also form an ether bond, a carbonyl group, an ester group), or any of the groups represented by the following general formulas (W1-1) to (W1-4).

[0171] [Chemical formula 18]

[0172]

[0173] In the above general formulas (W1-1) to (W1-4), R W is a divalent organic group having 1 to 23 carbon atoms, and #1 and #2 each represent a bonding portion to an ester and a benzene ring, respectively.

[0174] In the above general formula (T-1), 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 containing one or more double bonds or triple bonds, a hydroxyl group, an amino group, or a halogen atom. From the viewpoint of thermosetting properties, a hydroxyl group is preferred.

[0175] More specific examples of the formula (T-1) are shown below, but are not limited thereto. (In the following formulas, R1 and R w are the same groups as described above.)

[0176] [Chemical formula 19]

[0177]

[0178] In the above general formula (T-2), W2 is a substituted or unsubstituted linear / branched / cyclic saturated / unsaturated hydrocarbon group having 1 to 40 carbon atoms (including aromatic groups), 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, an amide group, and may also form a heterocyclic structure with an intervening amide group, ester group, etc. From the viewpoints of heat resistance and an increase in Sn content, W2 is preferably a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms (including aromatic groups) which may also contain a hydroxyl group or an amino group (the aforementioned hydrocarbon contains an oxygen atom, a nitrogen atom, a sulfur atom and may also form an ether bond, a carbonyl group, an ester group).

[0179] More specifically, W2 is preferably a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms (including aromatic ring groups) which may also contain a hydroxyl group or an amino group, or a cyclic hydrocarbon group bonded to 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 any of the groups represented by the following general formulas (W2-1) to (W2-4).

[0180] [Chemical formula 20]

[0181]

[0182] 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 each represent the bonding portions to the ester group and the carbon atom, respectively.

[0183] In the above general formula (T-2), s3 is 1 or 2. When s3 is 1, R3 is a hydrogen atom or a hydroxy group-containing hydrocarbon group having 1 to 10 carbon atoms. When s3 is 2, R3 is an oxygen atom and together with the carbon atom bonded thereto forms a carbonyl group. W2 and R3 may also bond to each other to form a ring structure. s2 is an integer of 0 to 1. From the viewpoint of increasing the tin content, it is preferable that s2 is 0. From the viewpoints of thermal fluidity and landfillability, it is better to contain an organic chain, so it is preferable that s2 is 1. Also, when s2 is 0, it means that the carbonyl group is bonded by a single bond.

[0184] Specific examples of (T-2) including W2 are shown below, but are not limited to these. (In the following formulas, R1 and R w represent the same groups as described above.)

[0185] [Chemical formula 21]

[0186]

[0187] 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, and the ideal structure of R W is, for example, as follows, but is not limited to these (* each represents the bonding portion to the carbon atom of the carbonyl group).

[0188] [Chemical formula 22]

[0189]

[0190] Furthermore, in the above 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.

[0191] If it is a metal-containing film-forming compound having such a structure, the thermosetting property can be further improved.

[0192] Also, in the above general formulas (W1-1) to (W1-4) and (W2-1) to (W2-4), if R W has the structure represented by the following general formula (1), it is more ideal from the viewpoints of thermosetting property and increasing the tin content.

[0193] [Chemical formula 23]

[0194]

[0195] 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 each represent the bonding part to the carbonyl group, and *1 and *2 may also be interchanged.

[0196] The carboxylic acid raw material containing the above general formula (1) can be synthesized by ring-opening a cyclic anhydride. However, when an asymmetric cyclic carboxylic anhydride is ring-opened, it will become a mixture of two types and have the bonding form as described above. Due to the existence of such isomers, the crystallinity can be inhibited, and an improvement in solvent solubility, an improvement in thermal fluidity, and an improvement in landfill characteristics can be expected. For example, in the ring-opening reaction of itaconic anhydride derivative shown below and 4-(2-aminoethyl)pyrocatechol, 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, resulting in a mixture of two isomers.

[0197] [Chemical formula 24]

[0198]

[0199] The compound represented by the above general formula (M) can be synthesized by condensing a tin-containing carboxylic acid unit (T), an alkyltin trichloride, a dialkyldichlorotin, a dialkyloxotin (Z), and a monovalent carboxylic acid (P) (Reactions 1 to 4). (R, R1, R2, R3, m, s1, s2, W1, W2 are as described above.)

[0200] (Reaction 1) For the case of condensing 3 equivalents of (T) with an alkyltin trichloride (Z).

[0201] [Chemical formula 25]

[0202]

[0203] (Reaction 2) For the case of condensing 2 equivalents of (T) with a dialkyldichlorotin (Z).

[0204] [Chemical formula 26]

[0205]

[0206] (Reaction 3) For the case of condensing 1 equivalent each of (T) and (P) with a dialkyloxotin (Z).

[0207] [Chemical formula 27]

[0208]

[0209] (Reaction 4) For the case of condensation by adding 2 equivalents of (T) and 1 equivalent of (P) to alkyltin trichloride (Z).

[0210] [Chemical formula 28]

[0211]

[0212] Also, when synthesizing using multiple (T)s, not only using (T) but also using (P) during the reaction, there will be (M)s where all (T)s in one molecule are the same (T), and (M)s where all are different (T)s. Therefore, n1 and n2 represent the proportion of the existence of their substituents in the reaction system. For example, when using 1 equivalent of alkyltin trichloride (Z) for (Z), 1 equivalent of acrylic acid for (P), and 2 equivalents of the following raw materials for (T), there will also be molecules all from (T), molecules such as (T):(P) = 2:1. If looking at the whole, it becomes the existence ratio like the feed ratio.

[0213] [Chemical formula 29]

[0214]

[0215] Also, in the above general formula (M), the compound of the unit represented by (T) can be synthesized by condensation using 1 equivalent each of a tin compound such as dialkyldichlorotin and dialkyloxotin (Z), and a compound (X) containing both adjacent hydroxyl groups (two hydroxyl groups adjacent with a 2-carbon atom interval) and a carboxylic acid (Reactions A1, A2). (R1, R2, R3, m, s1, s2, W1, W2 are as described above.)

[0216] (Reaction A1) General formula for the condensation of dialkyloxotin (Z) and catechol derivative (X)

[0217] [Chemical formula 30]

[0218]

[0219] (Reaction A2) General formula for the condensation of dialkyldichlorotin (Z) and diol derivative (X) (s3 = 1)

[0220] [Chemical formula 31]

[0221]

[0222] The condensation reactions (Reactions 1 to 4) using the above (T), (Z), and (P), and the condensation reactions (Reaction A (Reactions A1 and A2)) using (X) and (Z) can generally be carried out without a solvent or in a solvent at room temperature or with cooling or heating as required. Examples of the solvent used include ethers such as diethyl ether, dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; chlorinated solvents such as dichloromethane, chloroform, dichloroethane, and trichloroethylene; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, and isobutyl methyl ketone; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; lactones such as γ-butyrolactone; and aprotic polar solvents such as dimethyl sulfoxide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, and hexamethylphosphoric triamide. These solvents can be used alone or in combination 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. Also, the reaction temperature is preferably from -50°C to around the boiling point of the solvent, more preferably from room temperature to 130°C.

[0223] Also, when using a chlorine-containing substance as (Z), an alkali catalyst can be added as a catalyst. As the alkali catalyst that can be used, inorganic salts such as potassium carbonate and sodium hydroxide can be used, but since they are difficult to remove, it is better to use organic bases such as triethylamine, diisopropylethylamine, N,N-dimethylaniline, pyridine, and 4-dimethylaminopyridine. The amount used is preferably 1.0 to 1.2 equivalents, more preferably 1.0 to 1.1 equivalents, relative to the chlorine group contained. Here, 1 equivalent relative to the chlorine group contained means, for example, when using dialkyltin dichloride as (Z), 2.0 moles of the catalyst are added relative to 1 mole of dialkyltin dichloride.

[0224] As the condensation reaction method of Reaction A, there are methods of feeding (X), (Z), the solvent, and the catalyst in batches, methods of gradually dropping (Z) in the presence of (X), the solvent, and the catalyst, methods of gradually dropping the catalyst in the presence of (X), (Z), and the solvent, etc. The amount of (Z) used at this time is preferably 0.95 to 1.05 equivalents, more preferably 1.0 equivalent, relative to (X). After the condensation reaction of Reaction A is completed, in order to remove unreacted raw materials, catalysts, etc., steps such as raising the temperature of the reaction kettle to 130 to 230°C and removing volatile components at about 1 to 50 mmHg, and methods of separating impurities from the obtained compound using appropriate poor solvents and good solvents can also be added. Also, by adding additional (Z) and (P) to the reaction system after the completion of Reaction A, the above Reaction 3 or 4 can be continued. After the condensation reaction of Reaction 3 or 4 is completed, steps for removing impurities, etc. can be added in the same manner as the above purification method.

[0225] In the above general formula (M), P is *-OC(=O)R (where R represents a monovalent organic group, and * represents the bonding part with the Sn atom). When P is contained, R can be freely changed. Therefore, if a large-sized structure can be incorporated, improvement in solubility and thermal fluidity can be expected. Furthermore, a crosslinked structure can be introduced, so sublimates can be suppressed, and volume shrinkage that induces landfill degradation can also be expected to be suppressed. As the carboxylic acid raw material containing R, a monofunctional carboxylic acid such as a linear substituted or unsubstituted hydrocarbon group such as acetic acid, propionic acid, glycine, a branched substituted or unsubstituted hydrocarbon group such as trimethylacetic acid, 2-aminoisobutyric acid, a cyclic substituted or unsubstituted hydrocarbon group such as cyclopropanecarboxylic acid, 3,3-difluorocyclobutanecarboxylic acid, etc. can be used without particular limitation. However, 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 is removed by heat or acid to generate a hydroxyl group or a carboxyl group is more preferable.

[0226] Further, it is preferable that the aforementioned 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).

[0227] [Chemical formula 32]

[0228]

[0229] In the aforementioned general formulas (A-1) to (A-4), Y A1 and 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 (such as an aliphatic 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 in which a protecting group is removed by the action of either or both of acid and heat to generate one or more hydroxyl groups or carboxyl groups, and * represents the bonding part with the carbonyl group.

[0230] [Chemical formula 33]

[0231]

[0232] 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 acid and heat, and * represents the bonding part with ]Y A1 or Y A2 .

[0233] In the above general formulas (A-1) to (A-4), Y A1 and Y A2 may be the same as 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 (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 in which a protecting group is removed by the action of either or both of an acid and heat in the above general formula (2) to generate one or more hydroxyl groups or carboxyl groups. Considering the thermal fluidity and solubility, (A-4) is preferred. From the viewpoint of suppressing sublimation due to decomposition of the organic component in order to increase the tin content, (A-1) is preferred.

[0234] In the above general formulas (A-1) to (A-4), Y A1 and Y A2 have ideal structures such as the following structures, but are not limited thereto. In the following formulas, * a represents the bonding part with R A1 , and * b represents another bonding part.

[0235] [Chemical formula 34]

[0236]

[0237] In the above general formula (A-3), 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. From the viewpoints of suppressing sublimation and increasing the Sn content, a hydrogen atom is preferred.

[0238] In the above general formula (2), R A2 is an organic group in which a protecting group (a thermally acid-labile group) is removed by the action of either or both of an acid and heat. It is preferably a tertiary hydrocarbon group or a group that forms an acetal structure together with an adjacent oxygen atom, and particularly preferably a tertiary hydrocarbon group.

[0239] The aforementioned tertiary hydrocarbon group preferably has 4 to 20 carbon atoms. From the viewpoints of suppressing sublimates generated from thermal decomposition products and ease of raw material procurement, tert-butyl is particularly preferred. Specific examples are listed below, but are not limited thereto. Also, in the following formulas, * represents the atomic bond with an oxygen atom.

[0240] [Chemical Formula 35]

[0241]

[0242] [Chemical Formula 36]

[0243]

[0244] [Chemical Formula 37]

[0245]

[0246] [Chemical Formula 38]

[0247]

[0248] Specific examples of the group forming the acetal structure are listed below, but are not limited to these. Also, in the following formula, * represents a bond to an oxygen atom.

[0249] [Chemical Formula 39]

[0250]

[0251] [Chemical Formula 40]

[0252]

[0253] [Chemical Formula 41]

[0254]

[0255] In the case of such a metal-containing film-forming compound, a metal-containing film-forming compound excellent in solvent solubility and thermal fluidity is formed. Also, in the structure of R A1 contains a bulky organic group in which the protecting group is detached by the action of either or both of an acid and heat. Therefore, when it is used in a metal-containing film-forming composition, they are detached during baking, so the tin content increases, and it becomes a metal-containing film-forming compound excellent in dry etching resistance. Furthermore, due to the generated hydroxyl groups and carboxyl groups by detachment, and due to the presence of the terminal OH group and α-hydrogen, it is easy to react with the radicals generated by the cleavage of the tin-carbon bond during baking, causing a crosslinking reaction, and has excellent thermosetting properties. Therefore, volume shrinkage can be suppressed, and a metal-containing film-forming composition such as an underlayer film material for a resist excellent in film-forming property and filling property even after high-temperature baking can be provided.

[0256] [Chemical Formula 42]

[0257]

[0258] 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 a bonding portion to a carbonyl group.

[0259] [Chemical formula 43]

[0260] B = * - Y B -R B (B)

[0261] In the above 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 (such as an aliphatic hydrocarbon group), 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, and R B is a hydroxyl group or any one of the structures represented by the following general formulas (B-1) to (B-3).

[0262] [Chemical formula 44]

[0263]

[0264] 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 with Y B .

[0265] 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 with the carbonyl group. In the above 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 (such as an aliphatic hydrocarbon group), 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, and 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 having 1 to 10 carbon atoms, and from the viewpoint of suppressing sublimation, a hydrogen atom is preferred.

[0266] The ideal structures of the above general formula (B) are, for example, as follows, but are not limited to these. Further, in the following formulas, * represents the atomic bond with the carbonyl group.

[0267] [Chemical formula 45]

[0268]

[0269] If it is such a metal-containing film-forming compound, it will be a metal-containing film-forming compound having excellent solvent solubility and thermal fluidity. Further, R BSince it contains a hydroxyl group or an unsaturated bond, when it is used in a metal-containing film-forming composition, crosslinking reactions will occur during baking. Therefore, it has excellent thermosetting properties. Furthermore, it will also react with the free radicals generated by the cleavage of the tin-carbon bond. Through this, the crosslinking reaction is promoted, and the thermosetting properties are excellent. Therefore, volume shrinkage can be inhibited, and a metal-containing film-forming composition with excellent film-forming properties and filling properties even after high-temperature baking can be provided.

[0270] [Chemical formula 46]

[0271]

[0272] In the above general formula (4), X is a divalent organic group having 1 to 31 carbon atoms, C is represented by the following general formulas (C-1) to (C-4), and * represents the bonding part to the carbonyl group.

[0273] [Chemical formula 47]

[0274]

[0275] In the above general formulas (C-1) and (C-3), R C1 is a hydrogen atom or a methyl group, and these 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 substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms (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. * represents the bonding part to the carbonyl group.

[0276] In the above general formula (4), X is a divalent organic group having 1 to 31 carbon atoms. Specifically, for example, a substituted or unsubstituted saturated divalent hydrocarbon group having 1 to 20 carbon atoms or an unsaturated divalent hydrocarbon group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, etc. C is the group represented by the above general formulas (C-1) to (C-4). In (C-1) and (C-3), from the viewpoint of considering the thermal fluidity, it is more preferable that R C1 is a methyl group, and from the viewpoint of considering the hardening property, a hydrogen atom is more preferable. Also, for R C2 in (C-3) and (C-4), from the viewpoint of considering the thermal fluidity, a structure as described above other than a hydrogen atom is more preferable.

[0277] In the above general formulas (C-1) to (C-4), the preferred structure of R C2 is, for example, as follows, but is not limited to these structures. Also, in the following formulas, * represents the atomic bond to the nitrogen atom.

[0278] [Chemical formula 48]

[0279]

[0280] In the case of a metal-containing film-forming compound having such a structure, since it contains the organic group represented by the above general formula (3), it becomes a metal-containing film-forming compound excellent in solvent solubility and heat resistance. Further, since it contains any one of the structures represented by the above general formulas (C-1) to (C-4) at the terminal, the crosslinking group density is high, and drastic volume shrinkage during baking can be reduced, and a metal-containing film-forming composition excellent in film-forming property and filling property can be provided.

[0281] In the metal-containing film formed using the composition containing the metal-containing film-forming compound (M), during baking, the Sn-C bond dissociates to generate radicals, and the hardening reaction proceeds due to the generated radicals (Equation 1). Therefore, for the promotion of the hardening reaction, the radicals need to re-bond with each other, so the hardening takes time or the generation efficiency of radicals at high temperature needs to be increased. However, since the compound of the present invention contains multiple tin atoms in one molecule, there are many active species, and the generation and re-bonding of radicals occur efficiently. Therefore, it has excellent heat resistance and thermosetting properties, and can provide an antireflective film excellent in film-forming property. Further, when P has a group containing an unsaturated bond or a hydroxyl group, not only do they react with radicals, but their groups alone also undergo a crosslinking reaction (Equation 2), so it becomes a film with even better heat resistance and excellent thermosetting properties.

[0282] [Chemical formula 49]

[0283]

[0284] [Chemical formula 50]

[0285]

[0286] Y in the above general formulas (A-1) to (A-4) A1 The ideal structures of X in the above general formula (2) or X in the above general formula (3) are, for example, the following structures, but are not limited to these structures. Further, in the following formulas, * represents the bonding part to the carbon atom of the carbonyl group or the * in formulas (A-1) to (A-4), formula (3), and formula (4).

[0287] [Chemical formula 51]

[0288]

[0289] Characterized in that Y in the above general formulas (A-1) to (A-4) A1 It is preferable that the metal-containing film-forming compound has an unsaturated hydrocarbon group having 2 to 23 carbon atoms for X in the above general formula (3) or X in the above general formula (4).

[0290] If Y in the above general formulas (A-1) to (A-4) A1When X in the above general formula (3) or X in the above general formula (4) is an unsaturated hydrocarbon group having 2 to 23 carbon atoms, the thermosetting property of the above metal-containing film-forming compound can be further improved.

[0291] Further, it is possible to provide a feature that Y in the above general formulas (A-1) to (A-4) A1 When 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).

[0292] [Chemical formula 52]

[0293]

[0294] 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 each represent a bonding portion to a carbonyl group, and *1 and *2 may also be interchanged.

[0295] For example, a carboxylic acid raw material containing the above general formula (1) can be synthesized by ring-opening an acid anhydride. However, when an asymmetric acid anhydride is ring-opened, it becomes a mixture of two types, so it becomes the above bonding form. Due to the existence of such isomers, crystallinity can be suppressed, and an improvement in solvent solubility, an improvement in thermal fluidity, and an improvement in flattening characteristics can be expected.

[0296] [Chemical formula 53]

[0297]

[0298] 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.

[0299] The ratio Mw / Mn (i.e., dispersity) of the weight-average molecular weight Mw to the number-average molecular weight Mn of the metal-containing film-forming compound in terms of polystyrene measured by gel permeation chromatography (GPC) using tetrahydrofuran is preferably in the range of 1.00 ≤ Mw / Mn ≤ 1.80, more preferably 1.00 ≤ Mw / Mn ≤ 1.50. By definition, for a single-molecule compound, Mw / Mn becomes 1.00, but due to the separation property of GPC, the measured value sometimes exceeds 1.00. Generally, for a polymer having repeating units, it is extremely difficult for Mw / Mn to be equal to 1.00 without using a special polymerization method, and there will be a distribution of Mw and Mw / Mn is a value exceeding 1. In the present invention, in order to distinguish a single-molecule compound and a polymer, for the index indicating single-molecule property, 1.00 ≤ Mw / Mn ≤ 1.50 is defined. Further, the above index can also be applied to a mixture of two or more kinds of the metal-containing film-forming compounds.

[0300] <Metal-containing film-forming composition>

[0301] Further, the present invention can provide a metal-containing film-forming composition which serves as an underlayer film material for a resist used in semiconductor manufacturing, and is characterized by containing the above-mentioned (a) metal-containing film-forming compound and (b) an organic solvent.

[0302] For such a metal-containing film-forming composition, 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 having excellent dry etching resistance compared to a known organic underlayer film material and having a high level of filling / planarization property can be formed.

[0303] The components contained in the metal-containing film-forming composition of the present invention other than the above-mentioned (a) metal-containing film-forming compound are described below.

[0304] <(b) Organic solvent>

[0305] The (b) organic solvent that can be used in the metal-containing film-forming composition of the present invention is not particularly limited as long as it can dissolve or disperse the above-mentioned (a) metal-containing film-forming compound, (c) crosslinking agent, (d) surfactant, (e) fluidity promoter, (f) acid generator, and other additives.

[0306] Specifically, the organic solvents described in paragraphs

[0091] to

[0092] of Japanese Patent Application Laid-Open No. 2007-199653 can be added. Further, specifically, it is preferable to use propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and γ-butyrolactone, or a mixture containing one or more of these.

[0307] (High-boiling solvent)

[0308] In the composition for forming an underlayer film of a resist, a mixture of one or more organic solvents having a boiling point (value at 1 atmosphere (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 be used as the aforementioned (b) organic solvent.

[0309] The high-boiling solvent only needs to be a solvent in which each component of the metal-containing film-forming composition of the present invention can be dissolved, and there are no special restrictions such as hydrocarbons, alcohols, ketones, esters, ethers, and chlorine-based solvents. Specific examples include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerol, n-nonyl acetate, monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-isobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol-n-butyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetin, propylene glycol diacetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-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.

[0310] A high-boiling solvent can be appropriately selected from the above, for example, in accordance with the temperature for heat-treating the composition for forming the lower resist film. It is preferable that the boiling point of the high-boiling solvent is 180°C to 300°C, and more preferably 200°C to 300°C. If the boiling point is within such a range, it is considered that there is no risk of excessive volatilization during baking (heat treatment), so sufficient thermal fluidity can be obtained during film formation, and a lower resist film with excellent filling / planarization characteristics can be formed. Also, if the boiling point is within such a range, it will not remain unvolatile in the film after baking, so there is no risk of adversely affecting film physical properties such as etching resistance.

[0311] The blending amount of the organic solvent is preferably 200 to 10,000 parts, more preferably 250 to 5,000 parts, relative to 100 parts by mass of the metal-containing film-forming compound (a).

[0312] Also, the blending amount when using a high-boiling solvent is preferably 1 to 30 parts by mass relative to 100 parts by mass of the organic solvent having a boiling point below 180°C. If the blending amount is within such a range, sufficient thermal fluidity can be imparted during baking, it will not remain in the film, and it will not cause deterioration of film physical properties such as etching resistance, so it is ideal.

[0313] <Composition for forming a lower resist film>

[0314] The above composition can be a composition for forming a lower resist film, which is a metal-containing film-forming composition that can be used as a lower resist film in a multilayer resist process, and further contains one or more of (c) a crosslinking agent, (d) a surfactant, (e) a fluidity promoter, and (f) an acid generator.

[0315] The components contained in the above composition for forming a lower resist film other than the above (a) metal-containing film-forming compound and (b) organic solvent are described below.

[0316] [(c) Crosslinking agent]

[0317] In the above composition for forming a lower resist film, in order to improve film densification and further to suppress cross-mixing with the upper resist film, (c) a crosslinking agent can be further contained. There are no special restrictions on the crosslinking agent, and various known crosslinking agents of different systems can be widely used. For example, 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 (such as 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, more preferably 10 to 40 parts by mass, relative to 100 parts by mass of the aforementioned (a) metal-containing film-forming compound.

[0318] Melamine - based cross - linking agents, specifically, for example, hexamethoxymethylated melamine, hexabutoxymethylated melamine, their alkoxy and / or hydroxy substituents, and their partial self - condensates.

[0319] Acrylate - based cross - linking agents, specifically, for example, di - neopentyl glycol hexacrylate.

[0320] Glycoluril - based cross - linking agents, specifically, for example, tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril, their alkoxy and / or hydroxy substituents, and their partial self - condensates.

[0321] Benzoguanamine - based cross - linking agents, specifically, for example, tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, their alkoxy and / or hydroxy substituents, and their partial self - condensates.

[0322] Urea - based cross - linking agents, specifically, for example, dimethoxymethylated dimethoxyethyleneurea, their alkoxy and / or hydroxy substituents, and their partial self - condensates. β - Hydroxyalkylamide - based cross - linking agents, specifically, for example, N,N,N’,N’ - tetra(2 - hydroxyethyl) adipamide.

[0323] Isocyanurate - based cross - linking agents, specifically, for example, tris(2,3 - epoxypropyl) isocyanurate, triallyl isocyanurate.

[0324] Aziridine - based cross - linking agents, specifically, for example, 4,4’ - bis(ethyleneiminocarbonylamino) diphenylmethane, 2,2 - bis(hydroxymethyl) butanol - tris[3 - (1 - aziridinyl) propionate].

[0325] Oxazoline - based cross - linking agents, specifically, for example, 2,2’ - isopropylidene bis(4 - benzyl - 2 - oxazoline), 2,2’ - isopropylidene bis(4 - phenyl - 2 - oxazoline), 2,2’ - isopropylidene bis(4 - phenyl - 2 - oxazoline), 2,2’ - methylene bis - 4,5 - diphenyl - 2 - oxazoline, 2,2’ - methylene bis - 4 - phenyl - 2 - oxazoline, 2,2’ - methylene bis - 4 - tert - butyl - 2 - oxazoline, 2,2’ - bis(2 - oxazoline), 1,3 - phenylene bis(2 - oxazoline), 1,4 - phenylene bis(2 - oxazoline), 2 - isopropenyl oxazoline copolymer.

[0326] Polynuclear phenol - based cross - linking agents, specifically, for example, compounds represented by the following general formula (XL - 1).

[0327] [Chemical formula 54]

[0328]

[0329] 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.

[0330] 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 preferably 2 or 3. Specifically, S is, for example, 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, or eicosane. R4 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Specifically, the alkyl group having 1 to 20 carbon atoms is, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, octyl, ethylhexyl, decyl, or eicosyl, and preferably a hydrogen atom or methyl.

[0331] Examples of the compound represented by the above general formula (XL-1) include the following compounds. From the viewpoints of improving the curability and film thickness uniformity of the organic film, the hexa-methoxymethylated products of triphenylmethane, triphenylethane, 1,1,1-tris(4-hydroxyphenyl)ethane, and tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene are preferred. R6 hereinafter is the same as R4 described above.

[0332] [Chemical formula 55]

[0333]

[0334] [Chemical formula 56]

[0335]

[0336] Epoxy-based crosslinking agents and oxetane-based crosslinking agents, such as monomeric and polymeric types. Specific examples of the monomeric type are listed below, but are not limited to these.

[0337] [Chemical formula 57]

[0338]

[0339] The above-mentioned compounds can be purchased. Epoxy crosslinking agents and oxetane crosslinking agents can also be obtained by reacting hydroxyl groups with epibromohydrin, 3-bromomethyloxetane, etc. according to the following formula. In the following formula, R5 is 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 arylalkylalkyl 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 preferable that the number of epoxy + oxetane > the number of hydroxyl groups, and more preferably the number of epoxy + oxetane > 2 × the number of hydroxyl groups. Also, the content of these compounds is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, based on 100 parts by mass of the metal-containing film-forming compound (a).

[0340] [Chemical formula 58]

[0341]

[0342] Examples of the hydroxyl group-containing compounds that can be used in the above reaction are as follows, but are not limited to these.

[0343] [Chemical formula 59]

[0344]

[0345] Also, in the case of polymers, specifically, 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 not 100%, for other structural units, α,β-unsaturated carboxylic acid esters such as other acrylates, other methacrylates, other acrylamides, other methacrylamides, crotonates, maleates, itaconates, etc.; α,β-unsaturated carboxylic acids such as methacrylic acid, acrylic acid, maleic acid, itaconic acid, etc.; acrylonitrile; methacrylonitrile; α,β-unsaturated lactones such as 5,5-dimethyl-3-methylene-2-oxotetrahydrofuran; norbornene derivatives, tetracyclo[4.4.0.1 2,5 .1 7，10A structural unit of any one of cyclic olefins such as dodecene derivatives; α,β-unsaturated carboxylic anhydrides such as maleic anhydride and itaconic anhydride; allyl ethers; vinyl ethers; vinyl esters; vinyl silanes. Further, for these polymers, the weight-average molecular weight 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). Further, in terms of molecular weight and dispersity, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) in terms of polystyrene are determined by GPC using tetrahydrofuran as an eluent, and the dispersity (Mw / Mn) is calculated.

[0346] [Chemical formula 60]

[0347]

[0348] In the formula, R7 is a hydrogen atom or a methyl group, R8 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-.

[0349] In R7 in the above general formula (XL-2), from the viewpoint of curability, it is preferable that the number of groups of (2-1) to (2-3) > the number of hydrogen atoms, and more preferably that the number of groups of (2-1) to (2-3) > 2 × the number of hydrogen atoms.

[0350] [Chemical formula 61]

[0351]

[0352] In the formula, R7 is a hydrogen atom or a methyl group, and R9 is a group selected from the following formulas (2-1) to (2-3).

[0353] [Chemical formula 62]

[0354]

[0355] In the above formula, the dashed line represents an atomic bond.

[0356] <(d) Surfactant>

[0357] In the above resist underlayer film-forming composition, in order to improve the coating property of spin coating, (d) a surfactant can be added. As the surfactant, for example, those described in

[0142] to

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

[0358] <(e) Fluidity promoter>

[0359] Furthermore, other compounds and polymers may be further blended into the composition for forming the underlying resist film. The fluidity promoter, when mixed with the metal-containing film-forming compound of the present invention, has the effect of improving the film-forming property by spin coating and the filling property on a substrate with height differences. Moreover, it is preferable that the fluidity promoter is a material having a high carbon atom density and high etching resistance.

[0360] Such materials, such as 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, gallic acid, thymol, isothymol, 4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-dimethyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-diallyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-difluoro-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-diphenyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-dimethoxy-4,4'-(9H-fluorene-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, vinylnaphthalene, biphenyl, bisphenol, triphenol, dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norbornadiene, 5-vinylnorborn-2-ene, α-pinene, β-pinene, limonene and other phenolic resins, polyhydroxystyrene, polystyrene, polyvinylnaphthalene, polyvinylanthracene, polyvinylcarbazole, polyindene, polyvinylnaphthalene, polynorbornene, polycyclodecene, polytetracyclododecene, polytricyclo[2.2.1.0(2,6)]heptane (poly-nortricyclene), poly(meth)acrylate and copolymers thereof.Further, it is also possible to blend a naphthol dicyclopentadiene copolymer described in Japanese Patent Application Laid-Open No. 2004-205685, a fluorene bisphenol novolak resin described in Japanese Patent Application Laid-Open No. 2005-128509, an ethylene naphthalene copolymer described in Japanese Patent Application Laid-Open No. 2005-250434, a fullerene having a phenol 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 phenol compound described in Japanese Patent Application Laid-Open No. 2006-285095, a binaphthol 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.

[0361] Further, in the above-mentioned resist underlayer film-forming composition, as an additive for imparting filling / planarization characteristics, for example, 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 is preferable. It is more preferable that this thermal decomposable polymer contains a repeating unit having an acetal structure represented by the following general formula (DP1) or (DP1a).

[0362] [Chemical formula 63]

[0363]

[0364] In the formula, R 10 is a hydrogen atom or an optionally substituted saturated or unsaturated monovalent organic group having 1 to 30 carbon atoms. Y is a saturated or unsaturated divalent organic group having 2 to 30 carbon atoms.

[0365] [Chemical formula 64]

[0366]

[0367] 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.

[0368] <(f) Acid generator>

[0369] In order to further promote the detachment reaction, the above-described composition for forming an underlayer film of a resist may contain an acid generator (f). The acid generator (f) may be one that generates an acid upon thermal decomposition or one that generates an acid upon light irradiation, and either can be added. Specifically, materials described in paragraphs

[0061] to

[0085] of Japanese Patent Application Laid-Open No. 2007-199653 can be added, but are not limited thereto.

[0370] The above acid generator can 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 by mass, more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of the above-described metal-containing film-forming compound (a).

[0371] <Method for forming an underlayer film of a resist>

[0372] The present invention provides a method for forming an underlayer film of a resist or a filling film serving as a planarization film for semiconductor manufacturing using the above-described metal-containing film-forming composition to form a multilayer resist film for lithography.

[0373] In the method for forming an underlayer film of a resist using the metal-containing film-forming composition of the present invention, the above-described metal-containing film-forming composition is applied onto 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, the solvent is evaporated, and baking (heat treatment) is performed to prevent mixing with the upper layer resist film and the intermediate layer resist film and to 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, 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 for wafer processing in lithography is preferably set to 600°C or lower, more preferably 500°C or lower.

[0374] Furthermore, in the method for forming an underlayer film of a resist using the metal-containing film-forming composition of the present invention, the metal-containing film-forming composition of the present invention can be applied onto a substrate to be processed by the same spin coating method or the like, and the metal-containing film-forming composition is fired in a gas environment with an oxygen concentration of 0.1% by volume or higher and 21% by volume or lower to be hardened to form a metal-containing film.

[0375] By firing the metal-containing film-forming composition of the present invention in such an oxygen environment, a sufficiently hardened film can be obtained. The gas environment during baking may be air, but in order to reduce oxygen, it is preferable to previously enclose an inert gas such as N2, Ar, or He to prevent oxidation of the metal-containing film. In order to prevent oxidation, it is necessary to control the oxygen concentration, preferably 1000 ppm or lower, more preferably 100 ppm or lower (volume basis). Preventing oxidation of the metal-containing film during baking is ideal because there is no increase in absorption and no decrease in etching resistance.

[0376] <Pattern formation method using a composition for forming an underlayer film of a resist>

[0377] Furthermore, the present invention provides a pattern formation method. As a pattern formation method performed by two-layer resist processing using the above-described metal-containing film-forming composition, a metal-containing film is formed on a substrate to be processed using the above-described 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 in the resist upper layer film, the resist upper layer film having the pattern transferred thereto is used as a mask, and the pattern is transferred to the metal-containing film by dry etching, and the processed substrate is processed using the metal-containing film having the pattern formed thereon as a mask to form a pattern on the processed substrate.

[0378] The resist upper layer film in the above two-layer resist processing shows resistance to etching with a chlorine-based gas. Therefore, in the above two-layer resist processing, it is preferable to use an etching gas mainly composed of a chlorine-based gas for the dry etching of the metal-containing film using the resist upper layer film as a mask.

[0379] Furthermore, the present invention provides a pattern formation method. As a pattern formation method performed by three-layer resist processing using such a metal-containing film-forming composition, it is characterized in that: a metal-containing film is formed on a substrate to be processed using the above-described metal-containing film-forming composition, a resist intermediate film (a 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 in the resist upper layer film, the resist upper layer film having the pattern formed thereon is used as a mask, and the pattern is transferred to the resist intermediate film by dry etching, the resist intermediate film having the pattern formed thereon is used as a mask, and the pattern is transferred to the metal-containing film by dry etching, and the processed substrate is processed using the metal-containing film having the pattern formed thereon as a mask to form a pattern on the processed substrate. Hereinafter, the case where a silicon-containing resist intermediate film is used as the resist intermediate film will be described as an example.

[0380] Regarding an example of three-layer resist processing, use Figure 1 is specifically disclosed as follows. In the case of three-layer resist processing, as shown in (A) of Figure 1 , after a metal-containing film (a metal-containing resist underlayer film) 3 is formed on a processed layer 2 laminated on a substrate to be processed 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.

[0381] Next, as shown in Figure 1As shown in (B) of , an important part (exposed part) 6 of the upper resist film 5 is exposed, and PEB and development are performed to form an upper resist film pattern 5a ( Figure 1 as shown in (C) of ). Using this obtained upper resist 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 as shown in (D) of ). After removing the upper resist film pattern 5a, using this obtained silicon-containing resist intermediate film pattern 4a as a mask, chlorine plasma etching is performed on the metal-containing film 3 to form a metal-containing film pattern (metal-containing lower resist film pattern) 3a ( Figure 1 as shown in (E) of ). After removing the silicon-containing resist intermediate film pattern 4a, using the metal-containing film pattern 3a as a mask, the layer to be processed 2 is etched to form a pattern 2a on the layer to be processed ( Figure 1 as shown in (F) of ).

[0382] The above-mentioned silicon-containing resist intermediate film treated with three-layer resist shows resistance to etching using chlorine-based gas and hydrogen-based gas. Therefore, in the above-mentioned three-layer resist treatment, for the dry etching of the metal-containing film using the silicon-containing resist intermediate film as a mask, it is preferably carried out using an etching gas mainly composed of chlorine-based gas or hydrogen-based gas.

[0383] The above-mentioned silicon-containing resist intermediate film treated with three-layer resist is also preferably 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 applications, if an organic film is used and a material with a large amount of aromatic groups and high substrate etching selectivity is used, the k value will increase and the substrate reflection will increase. However, by making the silicon-containing resist intermediate film have an absorption that becomes an appropriate k value to suppress reflection, the substrate reflection can be made 0.5% or less. For the silicon-containing resist intermediate film with an antireflection effect, for 248 nm and 157 nm exposure applications, it is preferably a polyhedral silsesquioxane with anthracene as a pendant group, and for 193 nm exposure applications, it is preferably a polyhedral silsesquioxane with a phenyl group or a light-absorbing group with a silicon-silicon bond as a pendant group and crosslinked with acid or heat.

[0384] In addition, the present invention provides a pattern formation method, which is a pattern formation method using a four-layer resist treatment using such a composition for forming a metal oxide film, and is characterized by having the following steps:

[0385] A metal-containing film is formed on a substrate to be processed using the above-described metal-containing film-forming composition. A silicon-containing resist intermediate film is formed on the resist underlayer film using a silicon-containing resist intermediate film material. An organic anti-reflection film (BARC) or a conformal film is formed on the silicon-containing resist intermediate film, and a resist upper layer film is formed on the BARC using a photoresist material. After pattern exposure of the resist upper layer film, it is developed with a developer to form a pattern on the resist upper layer film. The patterned resist upper layer film is used as a mask, and the pattern is transferred to the BARC or conformal film and the silicon-containing resist intermediate film by dry etching. The patterned silicon-containing resist intermediate film is used as a mask, and the pattern is transferred to the metal-containing film by dry etching. The patterned metal-containing film is used as a mask, and the substrate to be processed is processed to form a pattern on the substrate to be processed.

[0386] Alternatively, an inorganic hard mask may be formed instead of the silicon-containing resist underlayer film. 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 resist upper layer film is formed on the inorganic hard mask using a photoresist composition, a circuit pattern is formed on the resist upper layer film, the patterned resist upper layer film is used as a mask, the inorganic hard mask is etched, the patterned inorganic hard mask is used as a mask, the metal-containing film is etched, and then the patterned metal-containing film is used as a mask to etch the object to be processed, and a pattern is formed on the object to be processed, and a semiconductor device circuit pattern can be formed on the substrate.

[0387] As described above, when an inorganic hard mask is formed on the 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, a method for forming a silicon nitride film is described in Japanese Patent Application 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. Also, it is most preferable to use a SiON film having a high anti-reflection film effect as the inorganic hard mask. Since the substrate temperature when forming the SiON film becomes 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 it can be a combination of an inorganic hard mask formed by a CVD method or an ALD method and a metal-containing film formed by a spin coating method.

[0388] As described above, a photoresist film can be formed as an upper resist film on the inorganic hard mask, but an organic anti-reflection film (BARC) or a planarization film can also be formed by spin coating on the inorganic hard mask, and a photoresist film can be formed thereon. In particular, when a SiON film is used as the inorganic hard mask, even in immersion exposure with a high NA exceeding 1.0, reflection can be suppressed by using a SiON film and a two-layer anti-reflection film of BARC. Another advantage of forming BARC is the effect of reducing the tailing of the photoresist pattern directly above the SiON film.

[0389] Furthermore, in the pattern formation method of the present invention which is a multi-layer resist process using the metal-containing film-forming composition as described above, a lower resist film is formed on a substrate to be processed, and after coating the metal-containing film-forming composition of the present invention on the lower resist film, a metal-containing film is formed by heat treatment. 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. The patterned upper resist film is used as a mask, and the pattern is transferred to the metal-containing film by dry etching. The metal-containing film with the transferred pattern is used as a mask, and the pattern is transferred to the lower resist film by dry etching. Then, the patterned lower resist film is used as a mask, and the substrate to be processed is processed to form a pattern on the substrate to be processed. Thus, a semiconductor device circuit pattern can be formed on the substrate.

[0390] As described above, a photoresist film can be formed as an upper resist film on the metal-containing film, and an organic planarization film can also be formed by spin coating on the metal-containing film, and a photoresist film can be formed thereon. In this case, the pattern can be transferred to the organic planarization film and the metal-containing film by dry etching.

[0391] As described above, when forming a resist underlayer film on a substrate to be processed, a resist underlayer film can be formed by using a method of using a coating-type organic underlayer film material, a CVD method, an ALD method, or the like. Examples of the coating-type organic underlayer film material include resins and compositions disclosed in Japanese Patent Application Laid-Open No. 2012-001687, Japanese Patent Application Laid-Open No. 2012-077295, Japanese Patent Application Laid-Open No. 2004-264710, Japanese Patent Application Laid-Open No. 2005-043471, Japanese Patent Application Laid-Open No. 2005-250434, Japanese Patent Application Laid-Open No. 2007-293294, Japanese Patent Application Laid-Open No. 2008-065303, Japanese Patent Application Laid-Open No. 2004-205685, Japanese Patent Application Laid-Open No. 2007-171895, Japanese Patent Application Laid-Open No. 2009-014816, Japanese Patent Application Laid-Open No. 2007-199653, Japanese Patent Application Laid-Open No. 2008-274250, Japanese Patent Application Laid-Open No. 2010-122656, Japanese Patent Application Laid-Open No. 2012-214720, Japanese Patent Application Laid-Open No. 2014-029435, International Publication No. 2012 / 077640, International Publication No. 2010 / 147155, International Publication No. 2012 / 077640, International Publication No. 2010 / 147155, International Publication No. 2012 / 176767, Japanese Patent Application Laid-Open No. 2005-128509, Japanese Patent Application Laid-Open No. 2006-259249, Japanese Patent Application Laid-Open No. 2006-259482, Japanese Patent Application Laid-Open No. 2006-293298, Japanese Patent Application Laid-Open No. 2007-316282, Japanese Patent Application Laid-Open No. 2012-145897, Japanese Patent Application Laid-Open No. 2017-119671, Japanese Patent Application Laid-Open No. 2019-044022, etc.

[0392] In the above multi-layer resist process, the resist upper layer film can be either positive or negative, and the same as the commonly used photoresist composition can be used. After spin-coating the photoresist composition, pre-baking is performed, but a range of 60 to 180 °C for 10 to 300 seconds is preferable. Thereafter, exposure is carried out in the usual manner, and further, post-exposure baking (PEB) and development are performed to obtain a resist pattern. Also, the thickness of the resist upper layer film is not particularly limited, and 30 to 500 nm is ideal, and particularly 50 to 400 nm is preferable.

[0393] Also, the exposure light is high-energy radiation with a wavelength of 300 nm or less, and specifically, excimer lasers of 248 nm, 193 nm, 157 nm, soft X-rays of 3 to 20 nm, electron beams, X-rays, etc. can be cited.

[0394] As a method for forming a pattern of the above resist upper layer film, it is preferable to form a pattern by optical lithography with a wavelength of 5 nm or more and 300 nm or less, direct drawing using an electron beam, nanoimprinting, or a combination thereof.

[0395] Further, the development method in the above-described pattern forming method is preferably alkali development or organic solvent development.

[0396] Then, the obtained resist pattern is used as a mask for etching. For the etching of the silicon-containing resist intermediate film and the inorganic hard mask in the three-layer resist process, a fluorocarbon-based gas is used with the upper resist pattern as a mask. Thereby, a silicon-containing resist intermediate film pattern and an inorganic hard mask pattern are formed.

[0397] Next, the obtained silicon-containing resist intermediate film pattern and inorganic hard mask pattern are used as masks for etching the metal-containing film. The etching of the metal-containing film is preferably performed using an etching gas mainly composed of a chlorine-based gas.

[0398] The etching of the next workpiece can also be performed by a conventional method. For example, if the workpiece is SiO2, SiN, or a silicon dioxide-based low dielectric constant insulating film, etching is performed using a fluorocarbon-based gas as the main component. When the substrate is etched with a fluorocarbon-based gas, the silicon-containing resist intermediate film pattern in the three-layer resist process is peeled off simultaneously during the substrate processing.

[0399] The metal-containing film obtained using the composition for forming a metal-containing film of the present invention has the characteristic of excellent etching resistance during the etching of this workpiece.

[0400] Further, the workpiece (processed substrate) is not particularly limited, and substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, Al, and films having a processed layer formed on the substrate can be used. For 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 usually 50 to 10,000 nm, particularly 100 to 5,000 nm can be formed. Further, when the processed layer is formed, different materials can be used for the substrate and the processed layer.

[0401] In the pattern formation method using the metal-containing film-forming composition of the present invention, it is preferable to use a processed substrate having a structure or height difference with a height of 30 nm or more. As described above, the metal-containing film-forming composition of the present invention has excellent filling / planarization characteristics, so even if the processed substrate 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. It is more ideal that the height of the structure or height difference possessed by the above-mentioned processed substrate is 30 nm or more, more preferably 50 nm or more, and still 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 using the metal-containing film-forming composition of the present invention to form a film and perform filling / planarization, the film thickness of the resist intermediate film and the resist upper layer film formed later can be made uniform, so it is easy to ensure the exposure depth tolerance (DOF) during optical lithography, which is very ideal.

[0402] <Tone inversion type pattern formation method using a metal-containing film-forming composition>

[0403] Furthermore, the present invention provides a tone inversion type pattern formation method. As a tone inversion type pattern formation using such a metal-containing film-forming composition, it is characterized by having the following steps: forming a resist lower layer film on a processed substrate, 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, after pattern exposure of the resist upper layer film, developing with a developer to form a pattern in the resist upper layer film, using the patterned resist upper layer film as a mask, dry etching to transfer the pattern to the resist intermediate film or the organic thin film and the inorganic hard mask intermediate film, using the patterned resist intermediate film or the inorganic hard mask intermediate film as a mask, dry etching to transfer the pattern to the resist lower layer film, coating a metal-containing film on the patterned resist lower layer film using the above-mentioned metal-containing film-forming composition, filling the space between the patterns of the resist lower layer film with the metal-containing film, chemically stripping or dry etching and etching back the metal-containing film coated on the patterned resist lower layer film to expose the top surface of the patterned resist lower layer film, dry etching to remove the resist intermediate film or the hard mask intermediate film remaining on the top surface of the resist lower layer film, dry etching to remove the patterned resist lower layer film with the exposed surface, forming an inverted pattern of the original pattern on the metal-containing film, using the metal-containing film with the formed inverted pattern as a mask, and processing the processed substrate to form an inverted pattern on the processed substrate.

[0404] For an example of the formation of a tone inversion type pattern, use Figure 2 Specifically, it is described as follows. AsFigure 2 As shown in (G), 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.

[0405] Next, as Figure 2 shown in (H), an important part (exposed part) 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)). Using this 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)). After removing the resist upper layer film pattern 5a, using this 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)).

[0406] 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, the metal-containing film 8 is formed by heat treatment, 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)). Then, the metal-containing film 8 covering the resist underlayer film pattern 7a made of a coating-type organic underlayer film material is chemically stripped or dry-etched back to expose the top surface of the resist underlayer film pattern 7a made of a coating-type organic underlayer film material ( Figure 2 shown in (M)). Then, 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)). Then, the resist underlayer film pattern 7a made of a coating-type organic underlayer film material is removed by dry etching, and an inverted pattern of the original pattern is formed on the metal-containing film (a metal-containing film pattern 8a obtained by inverting the resist underlayer film pattern) ( Figure 2 shown in (O)). After that, using the metal-containing film pattern 8a obtained by inverting the resist underlayer film pattern as a mask, the aforementioned processed substrate is processed to form a tone-inverted pattern on the aforementioned processed substrate ( Figure 2 shown in (P)).

[0407] As described above, when forming the underlayer film of the resist on the substrate to be processed, the underlayer film of the resist can be formed by using a method using a coating-type organic underlayer film material, CVD method, ALD method, etc. Examples of the coating-type organic underlayer film material include resins and compositions disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-1687, Japanese Patent Application Laid-Open No. 2012-77295, Japanese Patent Application Laid-Open No. 2004-264710, Japanese Patent Application Laid-Open No. 2005-043471, Japanese Patent Application Laid-Open No. 2005-250434, Japanese Patent Application Laid-Open No. 2007-293294, Japanese Patent Application Laid-Open No. 2008-65303, Japanese Patent Application Laid-Open No. 2004-205685, Japanese Patent Application Laid-Open No. 2007-171895, Japanese Patent Application Laid-Open No. 2009-14816, Japanese Patent Application Laid-Open No. 2007-199653, Japanese Patent Application Laid-Open No. 2008-274250, Japanese Patent Application Laid-Open No. 2010-122656, Japanese Patent Application Laid-Open No. 2012-214720, Japanese Patent Application Laid-Open No. 2014-29435, International Publication WO2012 / 077640, International Publication WO2010 / 147155, International Publication WO2012 / 077640, International Publication WO2010 / 147155, International Publication WO2012 / 176767, Japanese Patent Application Laid-Open No. 2005-128509, Japanese Patent Application Laid-Open No. 2006-259249, Japanese Patent Application Laid-Open No. 2006-259482, Japanese Patent Application Laid-Open No. 2006-293298, Japanese Patent Application Laid-Open No. 2007-316282, Japanese Patent Application Laid-Open No. 2012-145897, Japanese Patent Application Laid-Open No. 2017-119671, Japanese Patent Application Laid-Open No. 2019-44022, etc.

[0408] In the above-described tone inversion type pattern forming method, after coating the composition for forming a metal-containing film on the obtained underlayer film pattern of the resist, in order to expose the top surface of the underlayer film pattern of the resist, it is preferable to remove the metal-containing film using a dry etching gas mainly composed of a chlorine-based gas. Thereafter, the resist intermediate film or the hard mask intermediate film remaining on the above underlayer film of the resist is dry-etched and removed using a fluorocarbon-based gas, and the underlayer film pattern of the resist whose surface is exposed is dry-etched and removed using an oxygen-based gas to form a metal-containing film pattern.

[0409] In the above-described tone inversion type pattern forming method, it is preferable that the resist underlayer film pattern has a structure or height difference of 30 nm or more. As described above, since the metal-containing film forming composition of the present invention has excellent filling / planarizing properties, even if the film to be processed has a structure or height difference (concavo-convex) of 30 nm or more, a flat hardened film can still be formed. It is more desirable that the height of the structure or height difference of the resist underlayer film pattern is 30 nm or more, more preferably 50 nm or more, and even 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 for filling / planarizing, pattern inversion / transfer can be performed with high precision, so it is very desirable. Compared with the resist underlayer film using a known coating type organic underlayer film material, the dry etching resistance using a fluorine-based gas is excellent. Therefore, by inverting the resist underlayer film pattern with the above metal-containing film forming composition, a desired resist pattern can be formed on the film to be processed with high precision.

[0410] [Examples]

[0411] Synthesis examples, comparative synthesis examples, examples, and comparative examples are given below for more specific description of the present invention, but the present invention is not limited to these examples. Also, the molecular weight and dispersity are obtained by measuring the weight-average molecular weight (Mw) and number-average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography (GPC) using tetrahydrofuran as an eluent, and the dispersity (Mw / Mn) is obtained.

[0412] [Synthesis Example]

[0413] The following synthesis examples and comparative examples use the tin compounds Sn shown below: (Sn-1) to (Sn-5), raw material group T: (TT1) to (TT14), and raw material group P: (P-1) to (P-6). Each raw material group is shown below. Also, for the compounds (TT2), (TT3), (TT5), and (P-3) below, if there are isomers as described above, only one structure is disclosed for representative purposes.

[0414] Tin compound Sn:

[0415] [Chemical Formula 65]

[0416]

[0417] nBu represents n-butyl, tBu represents tert-butyl, and Oc represents n-octyl.

[0418] Raw material group T:

[0419] [Chemical Formula 66]

[0420]

[0421] Raw material group P:

[0422] [Chemical formula 67]

[0423]

[0424] [Synthesis example 1] Synthesis of metal-containing film-forming compound (M-1)

[0425] (Reaction 1) Add 5.0 g of tin compound (Sn-1), 1.9 g of raw material (TT1) and 100 g of toluene, and react for 5 hours while removing water at 130 °C.

[0426] (Reaction 2) Return to room temperature, add 2.5 g of (Sn-1) additionally, and react for 5 hours while removing water at 130 °C. Remove toluene under reduced pressure, suspend in methanol, filter and wash to obtain compound (M-1).

[0427] [Synthesis examples 2-8] Synthesis of metal-containing film-forming compounds (M-2) to (M-8)

[0428] Change the tin compound and raw material T as shown in Table 1, and perform the same operations as in Synthesis example 1 to obtain metal-containing film-forming compounds (M-2) to (M-8).

[0429] [Table 1]

[0430]

[0431] [Synthesis example 9] Synthesis of metal-containing film-forming compound (M-9)

[0432] (Reaction 1) Add 5.0 g of tin compound (Sn-1), 3.1 g of raw material (TT9) and 100 g of toluene, and react for 5 hours while removing water at 130 °C.

[0433] (Reaction 2) Return to room temperature, add 2.8 g of (Sn-5) and 2.2 g of (P-1) additionally, and react for 12 hours at 130 °C. Remove toluene under reduced pressure, suspend in methanol, filter and wash to obtain compound (M-9).

[0434] [Synthesis examples 10-16] Synthesis of metal-containing film-forming compounds (M-10) to (M-16)

[0435] Change the tin compound and raw material T as shown in Table 2, and perform the same operations as in Synthesis example 9 to obtain metal-containing film-forming compounds (M-10) to (M-16).

[0436] [Table 2]

[0437]

[0438] [Chemical formula 68]

[0439]

[0440] In the above formula, Bn represents benzyl group.

[0441] [Synthesis of metal-containing film-forming compound (R-1) for comparative example]

[0442] 5.0 g of tin compound (Sn-1), 8.6 g of raw material group P (P-2) 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).

[0443] [Chemical formula 69]

[0444]

[0445] [Synthesis of metal-containing film-forming compound (R-2) for comparative example]

[0446] 5.0 g of tin compound (Sn-1), 6.8 g of raw material group T (TT14) 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).

[0447] [Chemical formula 70]

[0448]

[0449] [Weight-average molecular weight and dispersity]

[0450] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) of the above compounds (M-1) to (M-16), (R-1) and (R-2) were determined. The results are shown in Table 3. Also, the weight-average molecular weight Mw and number-average molecular weight Mn are polystyrene conversion values obtained by GPC method using tetrahydrofuran, and the dispersity was calculated from them.

[0451] [Table 3]

[0452]

[0453]

[0454] [Synthesis of metal-containing film-forming compound (R-3) for comparative example]

[0455] The tin compound reported in [Synthesis Example 8] of Japanese Patent No. 702894 was synthesized as a metal-containing compound presumably used for photoresist.

[0456] 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).

[0457] [Chemical Formula 71]

[0458]

[0459] [Synthesis of Metal-Containing Film-Forming Compound (R-4) for Comparative Example]

[0460] 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 dropwise add a mixed solution of 0.2 g of p-toluenesulfonic acid monohydrate and 3.0 g of PGME that has been pre-mixed and homogenized, and react at an internal temperature of 120 °C for 8 hours. After the reaction ends, return to room temperature, add 150 g of ultrapure water while stirring, let stand for 1 hour, and separate the upper layer. Further, dissolve in 30 g of PGME, and repeat the same operation 2 times. Then 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. After the reaction, remove the solvent under reduced pressure to obtain (R-4).

[0461] [Chemical Formula 72]

[0462]

[0463] [Synthesis of Metal-Containing Film-Forming Compound (R-5) for Comparative Example]

[0464] Synthesize the titanium compound reported in [Synthesis Example A-II] of Japanese Patent No. 6189758 as a metal-containing compound different from the metal-containing film-forming compound of the present invention.

[0465] To a solution of 284 g of titanium tetraisopropoxide (manufactured by Tokyo Chemical Industry Co., Ltd.) in 500 g of IPA (isopropyl alcohol), dropwise add a solution of 27 g of deionized water in 500 g of IPA with stirring at room temperature over 2 hours. Add 120 g of 2-methyl-2,4-pentanediol to the obtained solution, and stir at room temperature for 30 minutes. Concentrate this solution under reduced pressure at 30 °C, then heat to 60 °C, and continue heating under reduced pressure until no more distillate appears. At the point when no more distillate is seen, add 1,200 g of PGMEA, and continue heating at 40 °C under reduced pressure until no more IPA distills out to obtain 1,000 g of a PGMEA solution of titanium-containing compound (R-5) (compound concentration 20% by mass).

[0466] [Synthesis of Organic Film-Forming Resin (R-6) for Comparative Example]

[0467] In 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. Then, 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, it was cooled to room temperature, 2,000 ml of MIBK was added, and it was washed 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 then it was crystallized in 2,000 g of hexane. The precipitated crystals were separated by filtration, washed 2 times with 500 g of hexane and recovered. The recovered crystals were dried in vacuo at 70 °C to obtain a resin (R-6).

[0468] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0469] (R-6): Mw = 3,300, Mw / Mn = 2.54

[0470] [Chemical Formula 73]

[0471]

[0472] "Evaluation of Solvent Solubility and Heat Resistance"

[0473] Evaluation of the solvent solubility and heat resistance of metal-containing compounds.

[0474] The compounds (M-1) to (M-16) synthesized in Synthesis Examples 1 to 16 and the comparative compound (R-1) to (R-5) were each prepared as 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 ○, those with some undissolved were rated as Δ, and those that were completely suspended were rated as ×. Also, 3.0 mg was weighed separately, and using Thermo plus EVO2 of RIGAKU, in the atmosphere, the temperature was raised from 30 °C to 300 °C at 10 °C / min. At this time, those with a weight loss 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 loss of more than 60% were rated as C. These results are shown in Table 4.

[0475] [Table 4]

[0476]

[0477]

[0478] As shown in Table 4, it was confirmed that the metal-containing film-forming compounds (M-1) to (M-16) of the present invention can be prepared as a solution with cyclohexanone and have satisfactory solubility. Also, it was confirmed that the metal-containing film-forming compounds (M-9) to (M-16) with broken symmetry of the compounds can also be prepared as a solution with PGMEA and exhibit excellent solvent solubility. Similarly, the compound group of comparative examples excluding some elements of the present invention also showed the same solubility results, while (R-4) with a structure in which tin is introduced into the repeating unit of the polymer had no solubility at all. Also, in the TG-DTA measurement, the weight loss of the compounds of the present invention was 40% or less when the temperature was raised to 300 °C, but for the comparative example compounds, (R-2) had a weight loss of 49%, (R-3) had a weight loss of 68%, and (R-5) had a weight loss of 56%. It was confirmed that the compounds of the present invention have superior heat resistance in comparison.

[0479] [Metal-containing film-forming composition UDL-1]

[0480] The metal-containing film-forming compound (M-1) was dissolved in a solvent of cyclohexanone (CyHO) containing 0.5 mass% of the surfactant FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 5, and filtered through a 0.2 μm membrane filter to prepare a metal-containing film-forming composition (UDL-1).

[0481] [Preparation of metal-containing film-forming compositions (UDL-2 to 23) and metal-containing film-forming compositions for comparative examples (comparative example UDL-1 to 5)]

[0482] The types and contents of the respective components are as shown in Table 5, and the respective solutions were prepared by the same operations as UDL-1 except for this. Also, in Table 5, "-" indicates that the corresponding component was not used. The crosslinking agent used was the following formula (C-1), the high-boiling solvent (B2-1) used was 1,6-diacetoxyhexane: boiling point 260 °C, the polymer (E-1) for promoting fluidity was used, and the thermal acid generator (TAG) used was the following formula (F-1).

[0483] [Crosslinking agent]

[0484] The crosslinking agent (C-1) used in the metal-containing film-forming composition is as follows.

[0485] [Chemical formula 74]

[0486]

[0487] [Synthesis example of polymer for promoting fluidity] Synthesis of polymer (E-1) for promoting fluidity

[0488] In a nitrogen atmosphere, 20.0 g of cresol novolac varnish, 27.6 g of potassium carbonate, and 100 g of DMF were added, and a homogeneous dispersion was prepared at an internal temperature of 50°C. 11.9 g of propargyl bromide was slowly added, and the reaction was carried out at an internal temperature of 50°C for 24 hours. 300 ml of methyl isobutyl ketone and 300 g of pure water were added to the reaction solution to dissolve the precipitated salt, and then the separated aqueous layer was removed. Further, the organic layer was washed 6 times with 100 g of 3% aqueous nitric acid solution and 100 g of pure water, and then the organic layer was dried under reduced pressure to obtain resin (E-1).

[0489] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained. (E-1): Mw = 8,500, Mw / Mn = 3.46

[0490] [Chemical Formula 75]

[0491]

[0492] [Thermal Acid Generator]

[0493] The thermal acid generator (F-1) used in the metal-containing film-forming composition is as follows.

[0494]

[0495] [Table 5]

[0496]

[0497]

[0498] [Film-Forming Property Test]

[0499] The above-prepared metal-containing film-forming compositions (UDL-1 to 23, Comparative Examples UDL-1 to 4) were coated on a silicon substrate, fired at 180°C for 60 seconds, and then the film thickness (a [nm]) after firing at 250°C for 60 seconds was measured. The film thickness from the center to the periphery of the substrate was measured, the film thickness difference between the maximum and minimum film thicknesses, Range (b [nm]), was calculated, and the in-plane uniformity ((b / a) × 100) was determined.

[0500] Furthermore, PGMEA solvent was drop-coated thereon, left for 30 seconds and then spun dry, 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 determined. The results are shown in Table 6 below.

[0501] [Table 6]

[0502]

[0503]

[0504] As shown in Table 6, the in-plane uniformity of the metal-containing film-forming composition (Examples 1-1 to 1-23) of the present invention after high-temperature additional baking treatment at 250°C is 5.0% or less. It is confirmed that a film with few irregularities and flatness can be formed, and it is a film with excellent film-forming properties. On the other hand, in Comparative Examples 1-1 to 1-2 using Comparative Example Compound (R-1) having only 1 tin atom in one molecule without the T unit in the present invention and Comparative Example Compound (R-2) composed only of the T unit, the in-plane uniformity is also relatively good, but it is inferior to the Examples using the compound group of the present invention. It is considered that the reason is that there are few radical-active units of the Sn-alkyl bond, so crosslinking caused by radicals cannot occur efficiently, and irregularities on the film are caused by sublimates and decomposition products. Also, in Comparative Example 1-3 using Comparative Example Compound (R-3) having multiple tin atoms in one molecule but composed only of esters instead of diol units, due to insufficient molecular weight and the influence of sublimates, large irregularities appear on the film. In Comparative Example 1-4 of Comparative Example UDL-4 using the titanium compound (R-5) reported in [Synthesis Example A-II] of Japanese Patent No. 6189758, a film with many irregularities and an in-plane uniformity exceeding 5.0% after baking treatment is formed, and the film-forming property is poor. It is speculated that the reason is that the titanium compound lacks heat resistance, and there are many sublimates and large volume shrinkage, etc.

[0505] Also, in Examples 1-17 to 1-20 using UDL-17 to 20 added with a crosslinking agent (C-1), compared with Examples 1-5, 6, 8, and 10 using UDL-5, 6, 8, and 10 without adding the crosslinking agent (C-1), the in-plane uniformity is improved. The reason is considered to be that the crosslinking agent enables the crosslinking reaction to proceed more efficiently and can suppress the occurrence of sublimates and decomposition products. Also, in Example 1-22 using UDL-22 added with an acid generator (F-1), compared with Example 1-14 without adding the acid generator (F-1), the residual film rate after rework is high, indicating that the crosslinking reaction proceeds further. Also, in addition, when comparing the Examples added with a flow promoter and a high-boiling solvent with the Examples not added with a flow promoter and a high-boiling solvent, it can be confirmed that there is no significant difference in the in-plane uniformity and the residual film rate after rework.

[0506] [Landfill Property Evaluation]

[0507] The above-described metal-containing film-forming compositions (UDL-1 to 23) and Comparative Examples UDL-3 and 4 were respectively coated on a SiO2 wafer substrate having a dense line & space pattern (line width: 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 was a base substrate 9 (SiO2 wafer substrate) having a dense line & space pattern as shown in (Q) (top view) and (R) (cross-sectional view) of Figure 3 . The cross-sectional shape of each wafer substrate obtained by observing with a scanning electron microscope (S-4700) manufactured by Hitachi, Ltd. was observed to confirm whether the height difference substrate could be filled. The results are shown in Table 7. When using a metal-containing film-forming composition with poor filling characteristics, the height difference substrate could not be filled smoothly in this evaluation. When using a metal-containing film-forming composition with good filling characteristics, in this evaluation, as shown in (S) of Figure 3 , the space between the lines of the base substrate 9 having a dense line & space pattern could be filled without gaps. 〇 indicates that it can be filled without generating large pores, △ indicates that it can be filled but large pores occur, and × indicates that it cannot be filled.

[0508] [Table 7]

[0509]

[0510] As shown in Table 7, when Examples 2-1 to 2-23 using the resist metal-containing film-forming composition of the present invention were baked at 250 °C, the dense line & space pattern could be filled without generating pores, and good filling characteristics were confirmed. For Comparative Example 2-1 using Comparative Example UDL-3 with poor film-forming properties, it could not be filled. For Comparative Example 2-2 using Comparative Example UDL-4 containing the titanium compound (R-5) reported in [Synthesis Example A-II] of Japanese Patent No. 6189758, pores were observed at the bottom of the pattern. It is speculated that because the compound of the present invention has few sublimates and small volume shrinkage due to high-temperature baking as observed in the above heat resistance evaluation and film-forming property evaluation, the height difference can be filled without generating pores. However, for Comparative Examples UDL-3 and 4 lacking heat resistance, there are many sublimates and large volume shrinkage, resulting in the generation of pores or inability to fill.

[0511] [Tin Content / Etching Resistance Test]

[0512] The metal-containing film-forming compositions (UDL-1, 2, 5, 7, 13, 15 to 17, 19) prepared above and Comparative Examples UDL-1 to 2 with good in-plane uniformity and Comparative Example UDL-5 for organic film-forming compositions were coated on a silicon substrate and heated on a hot plate at 250°C for 60 seconds, and Comparative Example UDL-5 was heated for 120 seconds to form a metal-containing film and an organic film. The elemental ratio on the surface was calculated using XPS K-ALPHA Surface Analysis (manufactured by Thermo SCIENTIFIC) and converted to mass%. Also, an etching test using CF-based gas and O2-based gas was carried out under the following conditions for the examples to obtain the film thickness difference of the above films before and after etching. The results are shown in Table 8. Also, for etching, a dry etching apparatus TE-8500 manufactured by Tokyo Electron Limited was used.

[0513] The etching conditions for CF4-based gas are as follows.

[0514]

[0515] The etching conditions for O2-based gas are as follows.

[0516]

[0517] [Table 8]

[0518]

[0519] As shown in Table 8, it was confirmed that in Examples 3-1 to 3-9 using the resist metal-containing film-forming composition of the present invention, regardless of the presence or absence of additives, the tin content rate of the fired film exceeded 70 wt%. On the other hand, in Comparative Examples 3-1 and 3-2 using Comparative UDL-1 and 2 in which only one tin atom exists in one molecule, the tin content rate was slightly less than 55 wt%, and it was confirmed that the tin content rate was poor. Also, in Examples 3-1 to 3-5 using UDL-1, 2, 5, 7, 13 without additives, the tin content rate was 80 wt% or more, and it was found that the fired film had a high tin content rate. It was confirmed that by containing multiple tin atoms in one molecule, a film with a high tin content rate was formed, and it was expected to emit secondary electrons due to EUV light absorption. Also, in the evaluation of etching resistance, the higher the tin content rate, the better the etching resistance for both CF-based gas and O2-based gas. In particular, for O2 etching, compared with Comparative Example 3-3 of an organic-based lower layer film without tin, the etching resistance was significantly improved.

[0520] As described above, since the compound for forming a metal oxide film of the present invention is an organotin compound that achieves a high level of heat resistance and a high tin content, the metal-containing film-forming composition using this compound has excellent dry etching resistance compared to known organic underlayer film materials, and can provide an anti-resist underlayer film material that combines film-forming properties and filling properties, which is extremely useful as an anti-resist underlayer film material used in a multi-layer resist method and a reversal agent used in a tone inversion etching method.

[0521] This specification includes the following aspects.

[0522] [1]: A metal-containing film-forming compound, characterized in that the compound is represented by the following general formula (M),

[0523] [Chemical formula 77]

[0524]

[0525] In the general formula (M), T is independently represented by the following general formula (T-1) or (T-2), P is independently *OCOR (* represents the bonding part to the Sn atom, and R represents a monovalent organic group), Q is independently 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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, a halogen atom, or an alkoxy group having 1 to 20 carbon atoms; further, n1, n2, and n3 are integers satisfying n1≥1, n2≥0, n3≥1, and n1 + n2 + n3 = 4. When n1≥2, the Ts can be the same or different, when n2 = 2, the Ps can be the same or different, and when n3≥2, the Qs can be the same or different.

[0526] [Chemical formula 78]

[0527]

[0528] In the aforementioned general formulas (T-1) and (T-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, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, * is the bonding part with the Sn atom in the aforementioned general formula (M); W1 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group (including aromatic ring groups) having 1 to 40 carbon atoms, the aforementioned hydrocarbon group contains oxygen atoms, nitrogen atoms, sulfur atoms as heteroatoms, can also form ether bonds, carbonyl groups, ester groups, amide groups, 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, m is an integer of 0 to 1; W2 is a substituted or unsubstituted linear, branched or cyclic saturated or unsaturated hydrocarbon group (including aromatic ring groups) having 1 to 40 carbon atoms, the aforementioned hydrocarbon group contains oxygen atoms, nitrogen atoms, sulfur atoms as heteroatoms, can also form ether bonds, carbonyl groups, ester groups, amide groups, 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, when s3 is 1, R3 is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms with a hydroxyl group, when s3 is 2, R3 is an oxygen atom and together with the carbon atom bonded thereto forms a carbonyl group, and W2 and R3 can also bond to each other and form a ring structure.

[0529] [2]: The metal-containing film-forming compound as in [1], wherein, in the aforementioned general formula (T-1), W1 is 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 (the aforementioned hydrocarbon group contains oxygen atoms, nitrogen atoms, sulfur atoms, and can also form ether bonds, carbonyl groups, ester groups) or any of the groups represented by the following general formulas (W1-1) to (W1-4),

[0530] [Chemical formula 79]

[0531]

[0532] [3]: The metal-containing film-forming compound as in [1] or [2], wherein,

[0533] In the above general formula (T-2), W2 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group (including aromatic ring groups) having 1 to 10 carbon atoms which may also contain a hydroxyl group or an amino group, or a cyclic hydrocarbon group formed by bonding with R3 (the above 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 any of the groups represented by the following general formulas (W2-1) to (W2-4),

[0534] [Chemical formula 80]

[0535]

[0536] 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 each represent a bonding part with an ester group and a carbon atom.

[0537] [4]: A metal-containing film-forming compound as in [2], wherein

[0538] R in the above general formulas (W1-1) to (W1-4) W is an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

[0539] [5]: A metal-containing film-forming compound as in [4], wherein the above R W is a group represented by the following general formula (1),

[0540] [Chemical formula 81]

[0541]

[0542] 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 bond to form a cyclic substituent, and *1 and *2 each represent a bonding part with a carbonyl group, and *1 and *2 may also be interchanged.

[0543] [6]: A metal-containing film-forming compound as in [3], wherein R in the above general formulas (W2-1) to (W2-4) W is an unsaturated hydrocarbon group having 2 to 23 carbon atoms.

[0544] [7]: A metal-containing film-forming compound as in [6], wherein the above R W is a group represented by the following general formula (1),

[0545] [Chemical formula 82]

[0546]

[0547] 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 each represent a bonding portion to the carbonyl group, and *1 and *2 may be interchanged. [8]: A metal-containing film-forming compound according to any one of [1] to [7], wherein in the aforementioned general formula (M), n2 is 1, and R in *OCOR of P 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).

[0548] [Chemical formula 83]

[0549]

[0550] In the aforementioned general formulae (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, 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, and R A1 is an organic group in which a protecting group is removed by the action of any one or both of an acid and heat to generate one or more hydroxyl groups or carboxyl groups, and * represents a bonding portion to the carbonyl group.

[0551] [Chemical formula 84]

[0552]

[0553] In the aforementioned general formula (2), R A2 is an organic group in which a protecting group is removed by the action of any one or both of an acid and heat, and * represents a bonding portion to Y A1 or Y A2 .

[0554] [Chemical formula 85]

[0555]

[0556] 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 the carbonyl group.

[0557] [Chemical Formula 86]

[0558] B = *-Y B -R B (B)

[0559] In the general formula (B) above, 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, and R B is a hydroxyl group or any one of the structures represented by the following general formulas (B-1) to (B-3),

[0560] [Chemical Formula 87]

[0561]

[0562] 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 with Y B of the bond,

[0563] [Chemical Formula 88]

[0564]

[0565] 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 with the carbonyl group,

[0566] [Chemical Formula 89]

[0567]

[0568] 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 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 the bonding part with the carbonyl group.

[0569] [9]: A metal-containing film-forming compound as in [8], 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.

[0570]

[10] : A metal-containing film-forming compound as in [9], wherein,

[0571] 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),

[0572] [Chemical formula 90]

[0573]

[0574] 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 a bonding portion to a carbonyl group, and *1 and *2 may also be interchanged.

[0575]

[11] : A metal-containing film-forming composition, which is a metal-containing film-forming composition acting as an underlayer film material used in semiconductor manufacturing, characterized in that:

[0576] It contains (a) a metal-containing film-forming compound as in any one of [1] to

[10] and (b) an organic solvent.

[0577]

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

[11] , wherein,

[0578] The above composition is a metal-containing film-forming composition that can be used as an underlayer film in a multilayer resist process, and further contains one or more of (c) a crosslinking agent, (d) a surfactant, (e) a fluidity promoter, and (f) an acid generator.

[0579]

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

[11] or

[12] , wherein,

[0580] The above (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.

[0581]

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

[0582] (I-1) After coating a metal-containing film-forming composition as in any one of

[11] to

[13] on the substrate to be processed, a metal-containing film is formed by heat treatment,

[0583] (I-2) A resist upper layer film is formed on the aforementioned metal-containing film using a photoresist material.

[0584] (I-3) After subjecting the aforementioned resist upper layer film to pattern exposure, it is developed with a developer to form a pattern on the aforementioned resist upper layer film.

[0585] (I-4) Using the aforementioned patterned resist upper layer film as a mask, a pattern is transferred to the aforementioned metal-containing film by dry etching, and

[0586] (I-5) Using the aforementioned patterned metal-containing film as a mask, the aforementioned substrate to be processed is processed to form a pattern on the aforementioned substrate to be processed.

[0587]

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

[0588] (II-1) After coating a composition for forming a metal-containing film according to any one of

[11] to

[13] on the substrate to be processed, a metal-containing film is formed by heat treatment.

[0589] (II-2) A resist intermediate film is formed on the aforementioned metal-containing film.

[0590] (II-3) A resist upper layer film is formed on the aforementioned resist intermediate film using a photoresist material.

[0591] (II-4) After subjecting the aforementioned resist upper layer film to pattern exposure, it is developed with a developer to form a pattern on the aforementioned resist upper layer film.

[0592] (II-5) Using the aforementioned patterned resist upper layer film as a mask, a pattern is transferred to the aforementioned resist intermediate film by dry etching.

[0593] (II-6) Using the aforementioned resist intermediate film with the transferred pattern as a mask, a pattern is transferred to the aforementioned metal-containing film by dry etching, and

[0594] (II-7) Using the aforementioned patterned metal-containing film as a mask, the aforementioned substrate to be processed is processed to form a pattern on the aforementioned substrate to be processed.

[0595]

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

[0596] (III-1) After coating a composition for forming a metal-containing film according to any one of

[11] to

[13] on the substrate to be processed, a metal-containing film is formed by heat treatment.

[0597] (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.

[0598] (III-3) Form an organic thin film on the aforementioned inorganic hard mask intermediate film.

[0599] (III-4) Form a resist upper layer film on the aforementioned organic thin film using a photoresist material.

[0600] (III-5) After pattern exposure of the aforementioned resist upper layer film, develop it with a developer to form a pattern on the aforementioned resist upper layer film.

[0601] (III-6) Use the aforementioned patterned resist upper layer film as a mask to transfer the pattern to the aforementioned organic thin film and the aforementioned inorganic hard mask intermediate film by dry etching.

[0602] (III-7) Use the aforementioned patterned inorganic hard mask intermediate film as a mask to transfer the pattern to the aforementioned metal-containing film by dry etching, and

[0603] (III-8) Use the aforementioned patterned metal-containing film as a mask to process the aforementioned substrate to be processed and form a pattern on the aforementioned substrate to be processed.

[0604]

[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:

[0605] (IV-1) Form a resist lower layer film on the substrate to be processed.

[0606] (IV-2) After coating the composition for forming a metal-containing film according to any one of

[11] to

[13] on the aforementioned resist lower layer film, form a metal-containing film by heat treatment.

[0607] (IV-3) Form a resist upper layer film on the aforementioned metal-containing film using a photoresist material, or spin-coat an organic sealing film on the aforementioned metal-containing film and form a resist upper layer film using a photoresist material thereon.

[0608] (IV-4) After pattern exposure of the aforementioned resist upper layer film, develop it with a developer to form a pattern on the aforementioned resist upper layer film.

[0609] (IV-5) Use the aforementioned patterned resist upper layer film as a mask to transfer the pattern to the aforementioned metal-containing film, or the aforementioned organic sealing film and the aforementioned metal-containing film by dry etching.

[0610] (IV-6) Use the aforementioned patterned metal-containing film as a mask to transfer the pattern to the aforementioned resist lower layer film by dry etching, and

[0611] (IV-7) Using the previously formed patterned lower resist film as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed.

[0612]

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

[0613] (V-1) Forming a lower resist film on the substrate to be processed,

[0614] (V-2) Forming a resist intermediate film on the aforementioned 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,

[0615] (V-3) Using a photoresist material to form an upper resist film on the aforementioned resist intermediate film, or a combination of an inorganic hard mask intermediate film and an organic thin film,

[0616] (V-4) After subjecting the aforementioned upper resist film to pattern exposure, developing it with a developer to form a pattern on the aforementioned upper resist film,

[0617] (V-5) Using the previously formed patterned upper resist film as a mask, dry etching is used to transfer the pattern to the aforementioned resist intermediate film, or the aforementioned organic thin film and the aforementioned inorganic hard mask intermediate film,

[0618] (V-6) Using the previously transferred patterned resist intermediate film, or inorganic hard mask intermediate film as a mask, dry etching is used to transfer the pattern to the aforementioned lower resist film,

[0619] (V-7) After coating a metal-containing film forming composition according to any one of

[11] to

[13] on the previously formed patterned lower resist film, heat treatment is used to coat a metal-containing film, and the spaces between the patterns of the aforementioned lower resist film are filled with the aforementioned metal-containing film,

[0620] (V-8) Chemically stripping or dry etching back the metal-containing film coated on the previously formed patterned lower resist film to expose the top surface of the previously formed patterned lower resist film,

[0621] (V-9) Dry etching is used to remove the remaining resist intermediate film, or hard mask intermediate film on the top surface of the aforementioned lower resist film,

[0622] (V-10) Dry etching is used to remove the previously formed patterned lower resist film with the surface exposed to form an inverted pattern of the original pattern on the metal-containing film,

[0623] (V-11) Using the metal-containing film with the reversed pattern formed above as a mask, process the substrate to be processed to form a reversed pattern on the substrate to be processed.

[0624]

[19] : The pattern forming method as in

[16] or

[18] , wherein the inorganic hard mask intermediate film is formed by CVD method or ALD method.

[0625] Furthermore, 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 within the technical scope of the present invention.

[0626] Explanation of reference numerals

[0627] 1: Substrate to be processed

[0628] 2: Layer to be processed

[0629] 2a: Pattern (pattern formed on the layer to be processed)

[0630] 3: Metal-containing resist underlayer film

[0631] 3a: Pattern of metal-containing resist underlayer film

[0632] 4: Silicon-containing resist intermediate film

[0633] 4a: Pattern of silicon-containing resist intermediate film

[0634] 5: Resist upper layer film

[0635] 5a: Pattern of resist upper layer film

[0636] 6: Exposed part

[0637] 7: Resist underlayer film composed of a coating-type organic underlayer film material

[0638] 7a: Pattern of resist underlayer film composed of a coating-type organic underlayer film material

[0639] 8: Metal-containing film

[0640] 8a: Metal-containing film pattern obtained by reversing the resist underlayer film pattern

[0641] 9: Substrate having dense lines & spaces

[0642] 10: Metal-containing resist underlayer film

Claims

1. A metal-containing film-forming compound, characterized in that: The compound is represented by the following general formula (M): In the general formula (M), T is independently the following general formula (T-1) or (T-2), P is independently *OCOR (* represents a bonding portion to a Sn atom, and R represents a monovalent organic group), Q is independently 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 having one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, a halogen atom, or an alkoxy group having 1 to 20 carbon atoms; and n1, n2, and n3 are integers satisfying n1 ≥ 1, n2 ≥ 0, n3 ≥ 1, and n1 + n2 + n3 = 4, and when n1 ≥ 2, T may be the same or different, when n2 = 2, P may be the same or different, and when n3 ≥ 2, Q may be the same or different. In the general formulae (T-1) and (T-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; * is a bond to the Sn atom in the general formula (M); 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, the hydrocarbon group containing 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, or may 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 an 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 hydroxyl group, an amino group, or a halogen atom; s1 is an integer of 0 to 1, and m is an integer of 0 to 1; 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, the hydrocarbon group containing 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, or may form a heterocyclic structure with the heteroatom interrupted; 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 1 to 10 carbon atoms and having a hydroxyl group, when s3 is 2, R3 is an oxygen atom and forms a carbonyl group together with the carbon atom to which it is bonded, and W2 and R3 may be bonded to each other to form a ring structure.

2. The metal-containing film-forming compound according to claim 1, wherein In the general formula (T-1), W1 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group (including an aromatic ring group) having 1 to 10 carbon atoms and may contain a hydroxyl group or an amino group (the hydrocarbon group may contain an oxygen atom, a nitrogen atom or a sulfur atom and may form an ether bond, a carbonyl group or an ester group) or any 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 to an ester group, and #2 represents a bonding portion to a benzene ring.

3. The metal-containing film-forming compound according to claim 1, wherein In the general formula (T-2), W2 is a linear, branched or cyclic saturated or unsaturated hydrocarbon group (including an aromatic ring group) having 1 to 10 carbon atoms which may contain a hydroxyl group or an amino group, or a cyclic hydrocarbon group obtained by bonding with R3 (the hydrocarbon group contains an oxygen atom, a nitrogen atom, a sulfur atom, and may form an ether bond, a carbonyl group, or an ester group), or any 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 each represent a bonding portion with an ester group and a carbon atom.

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 and R b They may also be bonded to form a cyclic substituent; *1 and *2 each represent a bond to the carbonyl group, and *1 and *2 may be interchanged.

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 and R b They may also be bonded to form a cyclic substituent; *1 and *2 each represent a bond to the carbonyl group, and *1 and *2 may be interchanged.

8. The metal-containing film-forming compound according to claim 1, wherein In the general formula (M), n2 is 1, and R of *OCOR of P is any 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). In the general formulas (A-1) to (A-4), Y A1 , Y A2 Each of them may be the same as or different from each other, and is 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, * represents a bonding portion with a carbonyl group, In the general formula (2), R A2 is an organic group whose protecting group is removed by the action of either acid or heat or both, and * represents A1 or Y A2 The bonding part, In the general formula (3), X is a divalent organic group having 1 to 31 carbon atoms, B is the following general formula (B), * 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 of the structures represented by the following general formulae (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 part, 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), * 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, which 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, 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 a carbonyl group.

9. The metal-containing film-forming compound according to claim 8, 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.

10. The metal-containing film-forming compound according to claim 9, 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 and R b They may also be bonded to form a cyclic substituent; *1 and *2 each represent a bond to the carbonyl group, and *1 and *2 may be interchanged.

11. A metal-containing film-forming composition which functions as a resist underlayer film material used in semiconductor manufacturing, characterized in that: Contains (a) the metal-containing film-forming compound according to any one of claims 1 to 10 and (b) an organic solvent.

12. The metal-containing film-forming composition according to claim 11, 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.

13. The metal-containing film-forming composition according to claim 11, 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.

14. A method for forming a pattern on a processed substrate, characterized by comprising the following steps: (I-1) After applying the metal-containing film-forming composition according to claim 11 on a substrate to be processed, forming a metal-containing film by heat treatment, (I-2) forming a resist upper layer film on the metal-containing film using a photoresist material, (I-3) exposing the resist upper layer film to pattern exposure, and then developing the film 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 to dry-etch the transferred pattern on the metal-containing film, 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.

15. 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 After the metal-containing film-forming composition according to claim 11 is used, a metal-containing film is formed by heat treatment, (II-2) forming a resist intermediate film on the metal-containing film, (II-3) forming a resist upper layer film on the resist intermediate film using a photoresist material, (II-4) exposing the resist upper layer film to pattern exposure, and then developing the film 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 to dry-etch and transfer a pattern to the resist intermediate film, (II-6) using the resist intermediate film having the transferred pattern as a mask to dry-etch the transferred pattern on the metal-containing film, 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.

16. 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 After the metal-containing film-forming composition according to claim 11 is used, a metal-containing film is formed by heat treatment, (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) exposing the resist upper layer film to pattern exposure, and then developing the film 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 to dry-etch the transferred pattern on the organic thin film and the inorganic hard mask intermediate film, (III-7) using the inorganic hard mask intermediate film having the transferred pattern as a mask to dry-etch the transferred pattern on the metal-containing film, 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.

17. 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 the resist underlayer film After the metal-containing film-forming composition according to claim 11 is used, a metal-containing film is formed by heat treatment, (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) exposing the resist upper layer film to pattern exposure, and then developing the film 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 to dry-etch the metal-containing film, or the organic composite film and the metal-containing film to transfer the pattern, (IV-6) using the metal-containing film having the transferred pattern as a mask to dry-etch the transferred pattern on the resist underlayer film, 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.

18. 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 silicon oxide film, silicon nitride film and 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 the combination of the inorganic hard mask intermediate film and the organic thin film, (V-4) exposing the resist upper layer film to pattern exposure, and then developing the film with a developer to form a pattern on the resist upper layer film, (V-5) using the patterned resist upper film as a mask to dry-etch the resist intermediate film, or the organic thin film and the inorganic hard mask intermediate film to transfer the pattern, (V-6) using the resist intermediate film or inorganic hard mask intermediate film to which the pattern has been transferred as a mask, dry etching is performed on the resist lower film to transfer the pattern, (V-7) coating the patterned resist underlayer film After the metal-containing film-forming composition according to claim 11 is prepared, the metal-containing film is coated by heat treatment, and the space between the resist underlayer film patterns is filled with the metal-containing film, (V-8) chemically stripping the metal-containing film covering the patterned resist underlayer film or etching back the metal-containing film by dry etching to expose the top surface of the patterned resist underlayer film, (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 patterned resist underlayer film exposed on the surface by dry etching to form a reverse pattern of the original pattern on the metal-containing film, (V-11) The metal-containing film having the reverse pattern formed therein is used as a mask to process the substrate to form a reverse pattern on the substrate.

19. The pattern forming method according to claim 16, wherein the inorganic hard mask intermediate film is formed by a CVD method or an ALD method.

20. 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.

Images