JP7151943B2 - METAL COMPLEX, COMPOSITION, RESIST MATERIAL, PATTERN FORMATION METHOD AND ELECTRONIC DEVICE MANUFACTURING METHOD - Google Patents

Description

The present invention relates to a metal complex, a composition, a resist material, a pattern forming method, and an electronic device manufacturing method.

In the field of manufacturing semiconductors such as ICs and LSIs, the development of lithography techniques using radiation such as electron beams (EB) and extreme ultraviolet rays (EUV) is underway because it enables the formation of finer patterns. . Lithographic techniques using these radiations currently have the problem of low light source intensity, and the development of higher-sensitivity lithographic resist materials is required. As one technique for increasing the sensitivity of a lithography resist material, for example, a technique using metal oxide nanoparticles has been studied (see Patent Document 1). In this technique, metal oxide nanoparticles having a particle size of 20 nm or less absorb the radiation, thereby generating secondary electrons from the polymer or the like in the resist composition, which accelerates the decomposition of the photoacid generator. It functions as a more sensitive positive photoresist. However, there is a problem that the metal oxide nanoparticles tend to aggregate, the stability as an industrial material is poor, and the radiation absorption efficiency gradually decreases due to the aggregation of the metal oxide nanoparticles.

As another technique, for example, a technique using a metal complex is being studied (see Patent Document 2). In this technique, a metal complex of β-diketones generates a metal oxide upon exposure to radiation, and since it is insoluble in an alkaline developer, it functions as a negative photoresist. However, in reality, the generation efficiency of metal oxides by radiation irradiation is not sufficient, and the sensitivity that satisfies market demands has not been realized. Moreover, in practice, it is necessary to add a polymer having a relatively high molecular weight, and it is not suitable for producing an ultrafine pattern with a width of several nanometers.

As described above, in the lithographic technique using radiation, development of a resist material capable of forming a fine pattern while having high sensitivity has been demanded.

WO2016/088655 JP 2012-185485 A

The problem to be solved by the present invention is to provide a resist material that is highly sensitive and capable of forming fine patterns and that can be used for radiation lithography.

As a result of intensive studies to solve the above problems, the present inventors have found that by using a metal complex having an anion compound having a specific structure as a ligand, it is possible to achieve high sensitivity and a fine pattern. The inventors have found that a resist material that can be used for radiation lithography can be realized, and have completed the present invention.

That is, the present invention relates to a metal complex characterized by using an anion compound (A) represented by the following general formula (1) as a ligand.

［上記一般式（１）中、Ｒ^１及びＲ^２は、それぞれ独立に、炭素原子数１～９の脂肪族炭化水素基、アルコキシ基、アリール基、アラルキル基又はハロゲン原子を表す。ｍ、ｎ及びｐは、それぞれ独立に、０～４の整数を表す。Ｒ^１が複数ある場合、複数のＲ^１は互いに同じでも異なってもよい。Ｒ^２が複数ある場合、複数のＲ^２は互いに同じでも異なってもよい。Ｒ^３は、水素原子、炭素原子数１～９の脂肪族炭化水素基、又は炭化水素基上にアルコキシ基、ハロゲン基及び水酸基から選択される置換基を１以上有する構造部位を表す。Ｒ^４は、水酸基、炭素原子数１～９の脂肪族炭化水素基、アルコキシ基又はハロゲン原子を表す。Ｒ^４が複数ある場合、複数のＲ^４は互いに同じでも異なってもよい。］

[In the general formula (1), R ¹ and R ² each independently represent an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group or a halogen atom. m, n and p each independently represent an integer of 0 to 4; When there are multiple R ¹ s, the multiple R ^1s may be the same or different. When there are multiple R ² s, the multiple R ^2s may be the same or different. R ³ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a structural moiety having at least one substituent selected from an alkoxy group, a halogen group and a hydroxyl group on the hydrocarbon group. R ⁴ represents a hydroxyl group, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group or a halogen atom. When there are multiple R ⁴ s, the multiple R ^4s may be the same or different. ]

The present invention also relates to a composition characterized by containing a compound (a) represented by the following general formula (2) and a metal complex (b).

［上記一般式（２）中、Ｒ^１及びＲ^２は、それぞれ独立に、炭素原子数１～９の脂肪族炭化水素基、アルコキシ基、アリール基、アラルキル基又はハロゲン原子を表す。ｍ、ｎ及びｐは、それぞれ独立に、０～４の整数を表す。Ｒ^１が複数ある場合、複数のＲ^１は互いに同じでも異なってもよい。Ｒ^２が複数ある場合、複数のＲ^２は互いに同じでも異なってもよい。Ｒ^３は、水素原子、炭素原子数１～９の脂肪族炭化水素基、又は炭化水素基上にアルコキシ基、ハロゲン基及び水酸基から選択される置換基を１以上有する構造部位を表す。Ｒ^４は、水酸基、炭素原子数１～９の脂肪族炭化水素基、アルコキシ基又はハロゲン原子を表す。Ｒ^４が複数ある場合、複数のＲ^４は互いに同じでも異なってもよい。］

[In the general formula (2), R ¹ and R ² each independently represent an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group or a halogen atom. m, n and p each independently represent an integer of 0 to 4; When there are multiple R ¹ s, the multiple R ^1s may be the same or different. When there are multiple R ² s, the multiple R ^2s may be the same or different. R ³ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a structural moiety having at least one substituent selected from an alkoxy group, a halogen group and a hydroxyl group on the hydrocarbon group. R ⁴ represents a hydroxyl group, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group or a halogen atom. When there are multiple R ⁴ s, the multiple R ^4s may be the same or different. ]

The present invention also relates to a resist material using the metal complex or composition.

The present invention also relates to a pattern forming method using the resist material, and an electronic device manufacturing method including the pattern forming method.

ADVANTAGE OF THE INVENTION According to this invention, the resist material which can be used for radiation lithography which can form a fine pattern while having high sensitivity can be provided.

1 is a GPC chart of compound (a) obtained in Synthesis Example 1. FIG. 1 is a ¹³ C-NMR chart of compound (a) obtained in Synthesis Example 1. FIG. 1 is an FT-IR spectrum of the metal complex (1) solution obtained in Example 1. FIG.

An embodiment of the present invention will be described below. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within a range that does not impair the effects of the present invention.

The metal complex of the present invention is characterized by using an anion compound (A) represented by the following general formula (1) as a ligand.

［上記一般式（１）中、Ｒ^１及びＲ^２は、それぞれ独立に、炭素原子数１～９の脂肪族炭化水素基、アルコキシ基、アリール基、アラルキル基又はハロゲン原子を表す。ｍ、ｎ及びｐは、それぞれ独立に、０～４の整数を表す。Ｒ^１が複数ある場合、複数のＲ^１は互いに同じでも異なってもよい。Ｒ^２が複数ある場合、複数のＲ^２は互いに同じでも異なってもよい。Ｒ^３は、水素原子、炭素原子数１～９の脂肪族炭化水素基、又は炭化水素基上にアルコキシ基、ハロゲン基及び水酸基から選択される置換基を１以上有する構造部位を表す。Ｒ^４は、水酸基、炭素原子数１～９の脂肪族炭化水素基、アルコキシ基又はハロゲン原子を表す。Ｒ^４が複数ある場合、複数のＲ^４は互いに同じでも異なってもよい。］

[In the general formula (1), R ¹ and R ² each independently represent an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group or a halogen atom. m, n and p each independently represent an integer of 0 to 4; When there are multiple R ¹ s, the multiple R ^1s may be the same or different. When there are multiple R ² s, the multiple R ^2s may be the same or different. R ³ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a structural moiety having at least one substituent selected from an alkoxy group, a halogen group and a hydroxyl group on the hydrocarbon group. R ⁴ represents a hydroxyl group, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group or a halogen atom. When there are multiple R ⁴ s, the multiple R ^4s may be the same or different. ]

In general formula (1), R ¹ and R ² each independently represent an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group or a halogen atom. The aliphatic hydrocarbon group may be linear or may have a branched structure. Moreover, you may have a cyclo ring structure. More specific examples include methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, nonyl group and the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propyloxy group, a butoxy group, a pentyloxy group, a hexyloxy group and a cyclohexyloxy group. Examples of the aryl group include phenyl group, tolyl group, xylyl group, naphthyl group and anthryl group. Examples of the aralkyl group include a benzyl group, a phenylethyl group, a phenylpropyl group and a naphthylmethyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Among them, R ¹ and R ² are preferably alkyl groups having 1 to 4 carbon atoms, and particularly preferably methyl groups, because of their excellent ability to form fine patterns when used as a resist material. Further, m and n in Structural Formula (1) are integers of 0 to 4, preferably integers of 1 to 3, and particularly preferably 2. At this time, two R ¹ and two R ² are preferably bonded to the 2,5-positions of the phenolic hydroxyl group, respectively.

In the general formula (1), R ³ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, or one or more substituents on a hydrocarbon group selected from an alkoxy group, a halogen group and a hydroxyl group. represents the structural site with Examples of the aliphatic hydrocarbon group having 1 to 9 carbon atoms include those exemplified for R ¹ and R ² above. Further, the "structural moiety having one or more substituents selected from an alkoxy group, a halogen group and a hydroxyl group on the hydrocarbon group" includes a halogenated alkyl group, a halogenated aryl group, a 2-methoxyethoxy group, a 2-ethoxy Examples thereof include alkoxyalkoxy groups such as ethoxy groups, and alkylalkoxy groups substituted with hydroxy groups. Among them, it is preferable that R ³ is a hydrogen atom.

In general formula (1), R ⁴ represents a hydroxyl group, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group or a halogen atom. Specific examples of each include those exemplified for R ¹ and R ² above. Also, p represents an integer of 0 to 4. Among them, those in which p is 0 are preferable.

In the present invention, as the anion compound (A), one having the same structure may be used alone, or a plurality of compounds having different molecular structures may be used.

In the metal complex of the present invention, the type of central metal is not particularly limited, and a wide variety of metals can be used. As the metal complexes, one having the same central metal may be used alone, or a plurality of kinds having different central metals may be used. Specific examples of central metals include magnesium, aluminum, calcium, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, silver, cadmium, indium, tin, antimony, cesium, and hafnium. Among them, zirconium, tin, or hafnium is preferable. Moreover, the valence of the central metal is not particularly limited, and the complex may be of any valence.

The metal complex of the present invention may have a ligand other than the anion compound (A). Specific examples of other ligands include RO ^- (R is a hydrocarbon group having 1 to 10 carbon atoms), RCOO ^- (R is a hydrocarbon group having 1 to 10 carbon atoms), [R ¹ COCH ₂ COR ² ] ⁻ (R ¹ and R ² are each independently a hydrocarbon group having 1 to 10 carbon atoms), amine ligands, imine ligands, phosphine ligands, alkyl ligands, Examples include alkene ligands, alkyne ligands, aryl ligands, and the like. Among them, RO- ⁽ R is a hydrocarbon group having 1 to 22 carbon atoms) is preferable because it has excellent photosensitivity and alkali solubility when used as a resist material, and R is a hydrocarbon having 2 to 6 carbon atoms. It is preferably a group.

When the metal complex of the present invention has other ligands in addition to the anion compound (A), the ratio of the anion compound (A) to the other ligands is such that the effect of the present invention is Since it is sufficiently exhibited, the ratio of the anion compound (A) to the total of both is preferably 20 mol% or more, more preferably 50 mol% or more, and preferably 80 mol% or more. Especially preferred. Note that the ratio is the average value of the values in each molecule.

The method for producing the metal complex of the present invention is not particularly limited, and it may be produced by any method. For example, it can be produced by mixing a compound (a) represented by the following general formula (2) and a metal complex (b) as a raw material in a solvent.

［上記一般式（２）中、Ｒ^１及びＲ^２は、それぞれ独立に、炭素原子数１～９の脂肪族炭化水素基、アルコキシ基、アリール基、アラルキル基又はハロゲン原子を表す。ｍ、ｎ及びｐは、それぞれ独立に、０～４の整数を表す。Ｒ^１が複数ある場合、複数のＲ^１は互いに同じでも異なってもよい。Ｒ^２が複数ある場合、複数のＲ^２は互いに同じでも異なってもよい。Ｒ^３は、水素原子、炭素原子数１～９の脂肪族炭化水素基、又は炭化水素基上にアルコキシ基、ハロゲン基及び水酸基から選択される置換基を１以上有する構造部位を表す。Ｒ^４は、水酸基、炭素原子数１～９の脂肪族炭化水素基、アルコキシ基又はハロゲン原子を表す。Ｒ^４が複数ある場合、複数のＲ^４は互いに同じでも異なってもよい。］

[In the general formula (2), R ¹ and R ² each independently represent an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group or a halogen atom. m, n and p each independently represent an integer of 0 to 4; When there are multiple R ¹ s, the multiple R ^1s may be the same or different. When there are multiple R ² s, the multiple R ^2s may be the same or different. R ³ represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, or a structural moiety having at least one substituent selected from an alkoxy group, a halogen group and a hydroxyl group on the hydrocarbon group. R ⁴ represents a hydroxyl group, an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group or a halogen atom. When there are multiple R ⁴ s, the multiple R ^4s may be the same or different. ]

Each symbol in the general formula (2) has the same meaning as in the structural formula (1), and preferred forms are also the same as in the general formula (1). As the compound (a), one having the same structure may be used alone, or a plurality of types of compounds having different structures may be used in combination.

The compound (a) may be produced by any method, but as an example, for example, a phenol compound (a1) and a formylbenzoic acid (a2) are mixed in the presence of an acid catalyst, It can be obtained by polycondensation by heating in the range of 60 to 140° C. using a solvent depending on the conditions.

In addition to phenol, the phenol compound (a1) does not have one substituent such as an aliphatic hydrocarbon group having 1 to 9 carbon atoms, an alkoxy group, an aryl group, an aralkyl group or a halogen atom on the aromatic ring of phenol. and a compound having a plurality of Specific examples of these substituents include those exemplified as R ¹ and R ² in the structural formulas (1) and (2). Among them, it preferably has 1 to 3, more preferably 2, alkyl groups having 1 to 4 carbon atoms because of its excellent ability to form a fine pattern when used as a resist material. At this time, the two alkyl groups are preferably bonded to the 2,5-positions of the phenolic hydroxyl group, respectively. Moreover, as an alkyl group, a methyl group is particularly preferable.

The formylbenzoic acids (a2) are, for example, formylbenzoic acid, compounds having one or more hydroxyl groups, aliphatic hydrocarbon groups having 1 to 9 carbon atoms, alkoxy groups or halogen atoms on their aromatic rings, acetyl Examples include aromatic ketones having a carboxyl group such as benzoic acid, and compounds having one or more hydroxyl groups, aliphatic hydrocarbon groups having 1 to 9 carbon atoms, alkoxy groups or halogen atoms on their aromatic rings. Specific examples of the C 1-9 aliphatic hydrocarbon group, alkoxy group or halogen atom include those exemplified as R ⁴ in the structural formulas (1) and (2). Among them, formylbenzoic acid is preferable because of its excellent reactivity with the phenol compound (a1), and 4-formylbenzoic acid is more preferable because it has a molecular structure that facilitates coordination with the metal atom.

Acid catalysts used in the production of compound (a) include, for example, acetic acid, oxalic acid, sulfuric acid, hydrochloric acid, phenolsulfonic acid, p-toluenesulfonic acid, zinc acetate, and manganese acetate. These acid catalysts can be used alone or in combination of two or more. Among these acid catalysts, sulfuric acid and p-toluenesulfonic acid are preferable because of their excellent activity. The acid catalyst may be added before the reaction or during the reaction.

When a solvent is used in the production of the compound (a), specific examples thereof include carboxylic acid compounds such as formic acid, acetic acid, propionic acid, butyric acid, and valeric acid; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono Glycol ether compounds such as propyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol monophenyl ether; cyclic ethers such as 1,3-dioxane and 1,4-dioxane compounds; glycol ester compounds such as ethylene glycol acetate; ketone compounds such as acetone, methyl ethyl ketone and methyl isobutyl ketone; and aromatic hydrocarbons such as toluene and xylene. These solvents can be used alone or in combination of two or more. Moreover, among these solvents, acetic acid is preferable from the viewpoint of excellent solubility of the obtained compound.

The charging ratio [(a1)/(a2)] of the phenol compound (a1) and the formylbenzoic acid (a2) is determined by the removability of the unreacted phenol compound (a1) and the yield of the resulting compound (a). From the standpoint of excellent yield and purity, the molar ratio is preferably in the range of 1/0.8 to 1/0.2, more preferably in the range of 1/0.6 to 1/0.4.

After the reaction is completed, for example, the reaction product is put into a poor solvent (S1) in which the reaction product is insoluble or poorly soluble, and the resulting precipitate is filtered off to obtain a crude product, followed by the poor solvent (S1). The compound (a) can be purified and isolated. Further, when an aromatic hydrocarbon such as toluene or xylene is used as the reaction solvent, the product compound (a) is dissolved in the solvent by heating at 80° C. or higher. , the compound (a) can be isolated by filtering out crystals of the compound (a). In this case, the poor solvent (S1) and solvent (S2) may not be used.

Examples of the poor solvent (S1) include water; monoalcohols such as methanol, ethanol and propanol; aliphatic hydrocarbons such as n-hexane, n-heptane, n-octane and cyclohexane; aromatics such as toluene and xylene group hydrocarbons. Among these poor solvents (S1), water and methanol are preferable because they can efficiently remove the acid catalyst at the same time.

Examples of the solvent (S2) include monoalcohols such as methanol, ethanol and propanol; Polyols such as pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, trimethylene glycol, diethylene glycol, polyethylene glycol, and glycerin; 2-ethoxyethanol, glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol monophenyl ether; Cyclic ethers such as 3-dioxane and 1,4-dioxane; glycol esters such as ethylene glycol acetate; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Further, when water is used as the poor solvent (S1), acetone is preferable as the (S2). The poor solvent (S1) and the solvent (S2) may be used alone or in combination of two or more.

The purity of the compound (a) is preferably 90% or more, more preferably 94% or more, and 98% or more as calculated from a gel permeation chromatography (GPC) chart. is particularly preferred. The GPC measurement conditions are those described in Examples.

The metal complex (b) is not particularly limited as long as it can cause ligand exchange when mixed with the compound (a) to form the metal complex of the present invention, and a wide variety of metal complexes can be used. be able to. Moreover, the said metal complex (b) may be used individually by 1 type, and may use 2 or more types together. The central metal of the metal complex (b) includes magnesium, aluminum, calcium, titanium, chromium, manganese, iron, cobalt, nickel, copper, zinc, zirconium, silver, cadmium, indium and tin, as in the metal complex of the present invention. , antimony, cesium, hafnium, and the like. Among them, zirconium, tin, or hafnium is preferable. Moreover, the valence of the central metal is not particularly limited, and the complex may be of any valence.

^{[ _} R ¹ COCH ₂ COR ² ] ⁻ (R ¹ and R ² are each independently a hydrocarbon group having 1 to 10 carbon atoms), [R ¹ COCH ₂ COOR ² ] ⁻ (R ¹ and R ² are each independently a carbon hydrocarbon groups with 1 to 10 atoms), amine ligands, imine ligands, phosphine ligands, alkyl ligands, alkene ligands, alkyne ligands, aryl ligands A rank etc. are mentioned. Among them, RO ^- (R is a hydrocarbon group having 1 to 22 carbon atoms) is preferable, and R is 2 carbon atoms, because it has excellent photosensitivity and alkali solubility when the obtained metal complex is used as a resist material. ∼6 hydrocarbon groups are preferred.

Since the effect of the present invention is sufficiently exhibited, the mixing ratio of the compound (a) and the metal complex (b) is 1 mol of the central metal of the metal complex (b). is preferably in the range of 0.5 to 10 mol, more preferably in the range of 2 to 6 mol.

The solvent is not particularly limited as long as it can dissolve the compound (a) and the metal complex (b), and a wide variety of solvents can be used. Specific examples include monoalcohols such as methanol, ethanol, propanol and butanol; ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, Polyols such as 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, trimethylene glycol, diethylene glycol, polyethylene glycol, glycerin; 2-ethoxyethanol, ethylene glycol monomethyl ether, Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, ethylene glycol monophenyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether , diethylene glycol dipropyl ether and diethylene glycol dibutyl ether; ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and propylene glycol monopropyl ether acetate Propylene glycol alkyl ether acetate; Cyclic ethers such as tetrahydrofuran, 1,3-dioxane and 1,4-dioxane; Glycol esters such as ethylene glycol acetate; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; 2-Hydroxypropionic acid methyl, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl oxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3- Ester compounds such as methoxybutyl acetate, ethyl formate, ethyl acetate, butyl acetate, methyl acetoacetate and ethyl acetoacetate; and nitrile compounds such as acetonitrile, acrylonitrile, propionitrile and butyronitrile. One type of these solvents may be used alone, or a mixed solvent of two or more types may be used.

Although the amount of the solvent used is not particularly limited, it is preferably in the range of 1 to 500 parts by mass with respect to 1 part by mass of the raw material component of the metal complex.

There are no particular restrictions on the temperature conditions when the raw materials for the metal complex are mixed, and the mixture may be room temperature of about 20 to 25° C., or may be heated as necessary.

Formation of a metal complex can be confirmed, for example, from a peak at 1400 cm ⁻¹ in an IR spectrum.

The resist material containing the metal complex of the present invention may be a pre-produced metal complex, or the compound (a) and the metal complex (b), which are raw materials of the metal complex, are separately blended to form a resist material. A metal complex may be generated within.

The resist material of the invention may contain a solvent. Examples of the solvent species include those used when mixing the compound (a) and the metal complex (b). The amount of the solvent to be used is not particularly limited, and is appropriately adjusted according to the specific application. In particular, the solid content concentration in the resist material is preferably in the range of 0.1 to 50% by mass, since a uniform film thickness can be obtained when the resist is applied by spin coating or the like.

In the resist material of the present invention, since the anion compound (A), which is a ligand of the metal complex, has sufficient film-forming properties, the metal complex itself can be used as a resist material without using other resin components. However, if necessary, an alkali-soluble resin may be used. Examples of alkali-soluble resins include various novolak-type phenolic resins. When using an alkali-soluble resin, since the effects of the present invention are sufficiently exhibited, the ratio of the metal complex to the total weight of the metal complex and the alkali-soluble resin is preferably 50% by mass or more, It is more preferably 75% by mass or more, and particularly preferably 90% by mass or more.

The resist material of the present invention may contain other components as necessary. Specific examples of other components include curing agents, photoacid generators, photosensitizers, fillers, pigments, surfactants such as leveling agents, adhesion improvers, dissolution accelerators, and the like. When using these other components, the effect of the present invention is sufficiently exhibited, so the ratio of the metal complex to the total mass of components other than the solvent of the resist material is preferably 50% by mass or more, and 75% by mass. % or more, and particularly preferably 90 mass % or more.

Examples of the curing agent include melamine compounds, guanamine compounds, glycoluril compounds, urea compounds, resole resins, epoxy compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as alkenyl ether groups, acid anhydrides, and oxazoline compounds. etc.

Examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, compounds in which 1 to 6 methylol groups of hexamethylolmelamine are methoxymethylated, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, and hexamethylolmelamine. Examples thereof include compounds in which 1 to 6 methylol groups are acyloxymethylated.

Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, tetramethoxymethylbenzoguanamine, compounds in which 1 to 4 methylol groups of tetramethylolguanamine are methoxymethylated, tetramethoxyethylguanamine, tetraacyloxyguanamine, Examples include compounds in which 1 to 4 methylol groups of tetramethylolguanamine are acyloxymethylated.

Examples of the glycoluril compounds include 1,3,4,6-tetrakis(methoxymethyl)glycoluril, 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4,6-tetrakis (Hydroxymethyl) glycoluril and the like.

Examples of the urea compound include 1,3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea and 1,1,3,3-tetrakis(methoxymethyl)urea. mentioned.

Examples of the resole resin include alkylphenols such as phenol, cresol and xylenol, phenylphenol, resorcinol, biphenyl, bisphenols such as bisphenol A and bisphenol F, phenolic hydroxyl group-containing compounds such as naphthol and dihydroxynaphthalene, and aldehyde compounds. Examples include polymers obtained by reacting under alkaline catalytic conditions.

Examples of the epoxy compound include diglycidyloxynaphthalene, phenol novolak type epoxy resin, cresol novolak type epoxy resin, naphthol novolak type epoxy resin, naphthol-phenol co-condensation novolac type epoxy resin, naphthol-cresol co-condensation novolak type epoxy resin. , phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, 1,1-bis(2,7-diglycidyloxy-1-naphthyl) alkane, naphthylene ether type epoxy resin, triphenylmethane type epoxy resin, dicyclopentadiene -Phenol addition reaction type epoxy resins, phosphorus atom-containing epoxy resins, polyglycidyl ethers of co-condensates of phenolic hydroxyl group-containing compounds and alkoxy group-containing aromatic compounds, and the like.

Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, and the like.

Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide and 4,4'-oxybisazide.

Examples of compounds containing double bonds such as alkenyl ether groups include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, Vinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetra vinyl ether, sorbitol pentavinyl ether, trimethylolpropane trivinyl ether and the like.

Examples of the acid anhydride include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, 4 ,4′-(isopropylidene)diphthalic anhydride, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride and other aromatic acid anhydrides; tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride Alicyclic carboxylic acid anhydrides such as phthalic acid, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, dodecenylsuccinic anhydride, trialkyltetrahydrophthalic anhydride, and the like. The curing agents may be used singly or in combination of two or more.

The content of the curing agent in the resist material is preferably in the range of 5 to 50% by mass based on the solid content of the resist material. The solid content of the resist material refers to the total amount of components other than the solvent in the resist material.

Examples of the photoacid generator include onium salt compounds, sulfonimide compounds, halogen-containing compounds, diazoketone compounds, and the like. Of these, onium salt compounds are preferred.

Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts and pyridinium salts.

Examples of the sulfonium salts include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo[2.2.1]hept -2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium camphorsulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4- Cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexyl phenyldiphenylsulfonium camphorsulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methane Sulfonylphenyldiphenylsulfonium 2-bicyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium camphorsulfonate, triphenylsulfonium 2-(1 -adamantyl)-1,1-difluoroethanesulfonate, triphenylsulfonium 6-(1-adamantylcarbonyloxy)-1,1,2,2-tetrafluorohexane-1-sulfonate, triphenylsulfonium 6-(1-adamantylcarbonyl oxy)-1,1,2-trifluorobutane-1-sulfonate, triphenylsulfonium 2-(4-oxo-1-adamantylcarbonyloxy)-1,1,3,3,3-pentafluoropropane-1- sulfonate, triphenylsulfonium 2-bicyclo[2.2.1]hept-2-yl-1,1-difluoroethanesulfonate and the like.

Examples of the tetrahydrothiophenium salts include 1-(4-n-butoxynaphthalene-1-yl)tetrahydrothiophenium trifluoromethanesulfonate and 1-(4-n-butoxynaphthalene-1-yl)tetrahydrothiophenium. Nonafluoro-n-butanesulfonate, 1-(4-n-butoxynaphthalene-1-yl)tetrahydrothiophenium perfluoro-n-octanesulfonate, 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothio Phenium 2-bicyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium camphor sulfonates, 1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium trifluoromethanesulfonate, 1-(6-n-butoxynaphthalene-2-yl)tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1-(6-n-butoxynaphthalene-2-yl)tetrahydrothiophenium perfluoro-n-octanesulfonate, 1-(6-n-butoxynaphthalene-2-yl)tetrahydrothiophenium 2-bicyclo [2. 2.1] Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1-(6-n-butoxynaphthalene-2-yl)tetrahydrothiophenium camphorsulfonate, 1-(3,5 -dimethyl-4-hydroxyphenyl)tetrahydrothiophenium trifluoromethanesulfonate, 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1-(3,5-dimethyl -4-hydroxyphenyl)tetrahydrothiophenium perfluoro-n-octanesulfonate, 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium 2-bicyclo[2.2.1]hept-2- yl-1,1,2,2-tetrafluoroethanesulfonate, 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium camphorsulfonate and the like.

The content of the photoacid generator in the resist material is preferably in the range of 5 to 50% by mass based on the solid content of the resist material. The solid content of the resist material refers to the total amount of components other than the solvent in the resist material.

When the resist material of the present invention contains solid materials such as fillers and pigments, they are preferably dispersed and mixed using a dispersing device such as a dissolver, homogenizer, or three-roll mill. Moreover, in order to remove coarse particles and impurities, filtration can be performed using a mesh filter, a membrane filter, or the like.

The resist material of the present invention can be used for pattern formation in the same manner as a general resist material. As an example, for example, a step of forming a resist film using a resist material, a step of exposing the resist film, and a step of developing the exposed resist film with a developer to form a pattern. There is a way to go through.

In the step of forming the resist film, the coating method is not particularly limited, and any method such as spin coating, roll coating, flow coating, dip coating, spray coating, and doctor blade coating may be used. When the resist material contains a solvent, the solvent can be removed by, for example, pre-baking at a temperature of 60 to 150° C. after coating to obtain a coating film. Examples of the object to be coated include a silicon substrate, a silicon carbide substrate, a gallium nitride substrate, a transparent conductive film, and the like, and can be appropriately selected according to the application.

In the exposure step, exposure is performed through a pattern-drawn mask. Examples of exposure light sources include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. Since the resist material of the present invention has high sensitivity and can form a fine pattern, it can be publicly used for exposure with extreme ultraviolet rays and electron beams.

As the alkali developer used in the development step, those used for general alkali development can be widely used, and examples thereof include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, and the like. Inorganic alkaline substances; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; and cyclic amines such as pyrrole and pyreridine. An alcohol, a surfactant, or the like may be appropriately added to these alkaline developing solutions, if necessary. The alkali concentration of the alkali developer is usually preferably in the range of 2 to 5% by mass, and a 2.38% by mass aqueous solution of tetramethylammonium hydroxide is generally used.

The pattern forming method of the present invention is suitably used in the manufacturing process of electronic devices. Examples of the electronic devices include household electrical equipment, office automation equipment, media-related equipment, optical equipment, and communication equipment.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these.

<GPC measurement conditions>
Measuring device: "HLC-8220 GPC" manufactured by Tosoh Corporation
Column: "Shodex KF802" manufactured by Showa Denko Co., Ltd. (8.0 mm Φ × 300 mm)
+ "Shodex KF802" manufactured by Showa Denko Co., Ltd. (8.0 mm Φ × 300 mm)
+ "Shodex KF803" manufactured by Showa Denko Co., Ltd. (8.0 mm Φ × 300 mm)
+ "Shodex KF804" manufactured by Showa Denko Co., Ltd. (8.0 mm Φ × 300 mm)
Column temperature: 40°C
Detector: RI (differential refractometer)
Data processing: "GPC-8020 model II version 4.30" manufactured by Tosoh Corporation
Developing solvent: tetrahydrofuran Flow rate: 1.0 mL/min Sample: A 0.5% by mass tetrahydrofuran solution of the object to be measured filtered through a microfilter (100 μl)
Standard sample: Monodispersed polystyrene below

(Standard sample: monodisperse polystyrene)
"A-500" manufactured by Tosoh Corporation
"A-2500" manufactured by Tosoh Corporation
"A-5000" manufactured by Tosoh Corporation
"F-1" manufactured by Tosoh Corporation
"F-2" manufactured by Tosoh Corporation
"F-4" manufactured by Tosoh Corporation
"F-10" manufactured by Tosoh Corporation
"F-20" manufactured by Tosoh Corporation

< ¹³ C-NMR measurement conditions>
Device: JNM-ECA500 manufactured by JEOL Ltd.
Measurement mode: Decoupling with reverse gate Solvent: Deuterated dimethyl sulfoxide Pulse angle: 30° pulse Sample concentration: 30% by mass
Accumulation times: 4000 times Chemical shift standard: Peak of dimethyl sulfoxide: 39.5 ppm

Synthesis Example 1 Synthesis of compound (a) 293.2 g (2.4 mol) of 2,5-xylenol and 150 g (1 mol) of 4-formylbenzoic acid were placed in a 2000 ml four-necked flask equipped with a condenser and dissolved in 500 ml of acetic acid. let me After adding 5 ml of sulfuric acid while cooling in an ice bath, the mixture was heated to 100° C. with a mantle heater and reacted with stirring for 2 hours. After completion of the reaction, water was added to the resulting solution to precipitate a crude product. The crude product was then redissolved in acetone and reprecipitated by adding water. The precipitate was filtered off and dried in vacuum to obtain 292 g of compound (a) as pale pink crystals.

The obtained compound (a) was subjected to ¹³ C-NMR spectrum measurement, and was confirmed to be a compound represented by the following structural formula. Further, the purity calculated from the GPC chart was 95.3%. A GPC chart of compound (a) is shown in FIG. 1, and a ¹³ C-NMR chart is shown in FIG.

Example 1 Preparation of Metal Complex (1) Solution 0.20 g (0.48 mmol) of compound (a) obtained in Synthesis Example 1 and zirconium (IV)-dibutoxide (manufactured by Matsumoto Fine Chemicals Co., Ltd.) “Orgatics ZC-580” ) and 20 g of tetrahydrofuran were placed in a 30 ml screw tube and mixed at room temperature for 30 minutes. The resulting solution was subjected to microfiltration using a polytetrafluoroethylene (PTFE) disk filter with a pore size of 0.1 μm to obtain a metal complex (1) solution. FIG. 3 shows the FT-IR spectrum of the obtained metal complex (1) solution.

Example 2 Production of Metal Complex (2) Solution The procedure of Example 1 was repeated except that zirconium (IV) dibutoxide was changed to 0.045 g (0.11 mmol) of hafnium (IV) isopropoxide monoisopropylate. to obtain a metal complex (2) solution.

Example 3 Production of metal complex (3) solution Metal complex (3) was prepared in the same manner as in Example 1, except that zirconium (IV) dibutoxide was changed to 0.045 g (0.11 mmol) of tetra-n-butoxytin. ) to give a solution.

Comparative Synthesis Example 1 Synthesis of Silsesquioxane Resin A 300 mL four-necked flask was charged with 25.0 g of ion-exchanged water, 93.6 g of 2-propanol (manufactured by Kanto Kagaku Co., Ltd.), and 0.2 g of 35% hydrochloric acid (manufactured by Sigma-Aldrich). 2 g was charged, and 75.1 g (0.42 mol) of methyltriethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) was added dropwise at 25° C. over 2 hours. The mixture was heated to 40° C. and stirred for 3 hours to obtain an oligomer solution. The weight average molecular weight of the obtained oligomer was 1,200. 6.6 g of ion-exchanged water and 1.1 g of 35% hydrochloric acid were added to the resulting oligomer solution, and the mixture was heated to 79° C. and stirred for 12 hours. After the obtained mixture was filtered through a filter paper with a filtration accuracy of 1 μm, 169 g of n-propyl acetate (manufactured by Kanto Kagaku Co., Ltd.) and 169 g of ion-exchanged water were added to the filtrate, followed by separation and washing. The n-propyl acetate phase was washed with 169 g of ion-exchanged water until the pH reached 4 or higher, filtered through a filter paper with a filtration accuracy of 1 μm, and the solvent was removed with a rotary evaporator to obtain 26.9 g of silsesquioxane resin powder. got The weight average molecular weight of the obtained silsesquioxane resin was 4,500.

0.5 g of the previously obtained silsesquioxane resin, 0.4 g of tetra(2,2,6,6-tetramethyl-3,5-heptanedionato)zirconium, 45.0 g of propylene glycol monopropyl ether, pure water5. 0 g was placed in a 100 m screw tube and mixed for 30 minutes at room temperature. Microfiltration was performed using a polytetrafluoroethylene (PTFE) disk filter with a pore size of 0.1 μm to obtain a metal complex (1′) solution.

Examples 4-6 and Comparative Example 1
The metal complex (1) to (3) solutions and the metal complex (1′) solution obtained above were used as resist materials and evaluated by the following methods. Table 1 shows the evaluation results.

Composite Evaluation 5 g of the metal complex solution was placed in a 30 ml heat-resistant tube, heated to 100° C. with shaking, and changed in state was observed. All of the solutions of metal complexes (1) to (3) of the invention of the present application were immobilized, whereas no change in viscosity was observed in the solution of metal complex (1').
Next, 1 g of 1N hydrochloric acid aqueous solution was added to the immobilized gelled metal complexes (1) to (3) solutions, and when the mixture was shaken at room temperature for 3 hours and the state change was observed, all changed to low viscosity liquids.

Electron Beam Patterning A hexamethylenedisilazane-treated silicon wafer with a diameter of 6 inches was coated using a spin coater. It was dried on a hot plate at 110° C. for 60 seconds to obtain a thin film with a thickness of 30 nm.
Using an ultra-high-speed electron beam writing system ("HL-800D" manufactured by Hitachi, Ltd.), the high voltage (HV) was set to 50 keV, and the exposure dose was changed stepwise in increments of 10 μC/ ^cm2 in the vacuum chamber. A line and space of 70 nm was drawn at a ratio of 1:1.
Immediately after drawing, post-exposure baking (PEB) is performed on a hot plate at 110° C. for 60 seconds, and puddle development is performed with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 20 seconds to form a negative pattern. Obtained.
Since the resist material of the present invention is not a chemically amplified resist material using an acid catalyst, the PEB process is not essential, but the PEB can promote the reaction of the metal salt to the metal oxide.

Evaluation of Sensitivity The patterns obtained were observed with a scanning electron microscope (SEM) and evaluated as follows. Evaluation criteria are as follows.
A: The amount of exposure for pattern development is less than 80 μC/cm ² B: The amount of exposure for pattern development is 80 μC/cm ² or more.

Evaluation of Edge Roughness (LWR) In the obtained pattern, edge roughness (LWR) of 70 nm line and space was evaluated with a scanning electron microscope (SEM). Evaluation criteria are as follows.
A: LWR is less than 3 nm B: LWR is 3 nm or more

Claims (10)

A metal complex comprising an anion compound (A) represented by the following general formula (1) as a ligand.

[In general formula (1) above, R ¹ and R ² each independently represent an alkyl group having 1 to 4 carbon atoms . m and n each independently represent an integer of 1 to 3 ; When there are multiple R ¹ s, the multiple R ^1s may be the same or different. When there are multiple R ² s, the multiple R ^2s may be the same or different. ] 2. The metal complex according to claim 1, wherein the central metal is zirconium, tin or hafnium. A composition comprising a compound (a) represented by the following general formula (2) and a metal complex (b).

[In the general formula (2), R ¹ and R ² each independently represent an alkyl group having 1 to 4 carbon atoms . m and n each independently represent an integer of 1 to 3 ; When there are multiple R ¹ s, the multiple R ^1s may be the same or different. When there are multiple R ² s, the multiple R ^2s may be the same or different. ] 4. The composition according to claim 3, wherein said metal complex (b) is one or more of a zirconium complex, a tin complex and a hafnium complex. 4. The composition according to claim 3, wherein said metal complex (b) is a metal alkoxide. A resist material containing the metal complex according to claim 1 . The composition according to any one of claims 3 to 5, which is a resist material. A step of forming a resist film using the resist material according to claim 6 or 7;
exposing the resist film;
and developing the exposed resist film with a developer to form a pattern. 9. The pattern forming method according to claim 8, wherein the exposure is exposure to an electron beam or extreme ultraviolet rays. A method for manufacturing an electronic device, comprising the pattern forming method according to claim 8 or 9.

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