Compound, photosensitive composition containing said compound, pattern forming method using said composition, substrate, and method for producing substrate

Abstract

Provided are: a compound with which it is possible to achieve miniaturization of a circuit pattern; and a photosensitive composition which contains said compound.　A compound according to the present invention has a metal atom and a ligand, and is characterized in that the ligand includes a partial structure that is represented by formula (1). In formula (1), R1 and R2 each represent a hydrogen atom or an arbitrary substituent, may be the same as or different from each other, and may form a ring. However, R1 and R2 are not hydrogen atoms at the same time. R3 represents an α-hydrogen-containing substituent on the oxygen side of the carbamate.

Description

Compound, photosensitive composition containing the compound, pattern forming method using the composition, substrate, and method for manufacturing substrate

[0001] The present invention relates to a compound suitable for use in ultra-microlithography processes such as those for producing VLSIs and high-capacity microchips, and other photofabrication processes, a photosensitive composition containing the compound, and a pattern formation method using the composition.

[0002] Traditionally, semiconductor device manufacturing processes involve fine processing using lithography with photoresist compositions. In semiconductor photolithography, circuit patterns become smaller as semiconductor devices become smaller, according to Moore's Law, and further miniaturization is desired. Photolithography is broadly based on the shortening of wavelengths of the light source used in exposure equipment and the photoresists that react to this wavelength. Photoresists are required to satisfy all of the following requirements: high resolution, low roughness, and high sensitivity. Conventional resists containing photoacid generators, known as chemically amplified resists, are thought to be unable to handle ultrafine patterns because acid diffusion leads to a decrease in resolution.

[0003] In recent years, therefore, non-chemically amplified photoresists based on compounds containing metal elements such as Zn and Sn have been proposed, and it has been reported that fine patterns can be formed using next-generation exposure equipment using extreme ultraviolet light (EUV light). For example, Patent Documents 1 and 2 and Non-Patent Documents 1 and 2 listed below disclose methods for forming resist patterns using extreme ultraviolet light (EUV light), electron beams, or the like.

[0004] JP 2022-123115 A JP 2024-26361 A

[0005] Miriam Sortland, et al., J. Micro / Nanolith. MEMS MOEMS 14(4), 043511, 2015.Yu Zhang et al., J. Photopolym. Sci. Technol., Vol. 31, No. 2, 2018

[0006] In photolithography, particularly in semiconductor photolithography, there is a demand for photosensitive compositions and pattern formation methods that can realize further miniaturization of circuit patterns. In particular, organic solvents are often used as developers to form ultrafine pattern structures. This is because aqueous developers can cause pattern collapse due to their high surface tension.

[0007] On the other hand, resist patterning can generally be selected between negative and positive types, but in the non-chemically amplified photoresists that have been reported to date aimed at ultrafine patterns, mainly negative pattern formation methods have been disclosed. As shown in the above prior art documents, in the positive pattern formation methods, an aqueous solvent is used as a developer, so there is a demand for improvements in resist materials to enable further miniaturization.

[0008] As a result of extensive research, the present inventors have found that a compound having a specific structure is suitable as a photoresist for ultrafine patterns. In particular, the present invention relates to a method for forming a positive pattern, but is a technology that enables further ultrafine patterning because it uses an organic solvent as a developer.

[0009] Therefore, an object of the present invention is to provide a compound capable of realizing finer positive circuit patterns, a photosensitive composition containing the compound, a pattern forming method using the photosensitive composition, a substrate using the pattern forming method, and a method for manufacturing a substrate.

[0010] The present invention has the following aspects [1] to

[21] .

[0011] [1] A compound having a metal atom and a ligand, wherein the ligand contains a partial structure represented by the following formula (1):

[0012]

[0013] In the above formula (1), R １ and R ２are hydrogen atoms or any substituents, and may be the same or different, and may form a ring. １ , R ２ cannot be a hydrogen atom at the same time. ３ represents an optionally substituted 2-propenyl group or an optionally substituted arylmethyl group.

[0014] [2] The compound according to claim 1 is a compound having a P block metal atom and a ligand, wherein the ligand contains a partial structure represented by the following formula (1):

[0015]

[0016] In the above formula (1), R １ and R ２ are hydrogen atoms or any substituents, and may be the same or different, and may form a ring. １ , R ２ cannot be a hydrogen atom at the same time. ３ represents an optionally substituted 2-propenyl group or an optionally substituted arylmethyl group.

[0017] [3] The compound according to [1] or [2], wherein the partial structure represented by formula (1) is the following formula (1-1) or (1-2):

[0018]

[0019] In the above formula (1-1), Ar is an aryl group, and R １６ ~R １９ are each independently a hydrogen atom or an arbitrary substituent, and may be the same or different.

[0020]

[0021] In the above formula (1-2), Ar is an aryl group, and R ３ is R in the above formula (1) ３ and R ２０ ~R ２２are each independently a hydrogen atom or an arbitrary substituent, and may be the same or different, and m is an integer of 0 or 1 or more.

[0022] [4] The compound according to [3], wherein the aryl group is represented by the following formula (2-1) or (2-2):

[0023]

[0024] In the above formula (2-1), R ４ ~R ８ are each independently a hydrogen atom or any substituent, and may be the same or different, at least one of which is a bond to Ar in the partial structure represented by the above formula (1-1) or (1-2). The dashed line represents a bond to the metal atom.

[0025]

[0026] In the above formula (2-2), R ９ ~R １５ are each independently a hydrogen atom or any substituent, and may be the same or different, and at least one of the substituents is a bond to Ar in the partial structure represented by the above formula (1-1) or (1-2). k represents an integer of 0 or 1 or more. The dashed line represents a bond to the metal atom.

[0027] [5] In the partial structure represented by the formula (1), R １ and R ２ The compound according to any one of [1] to [4], wherein

[0028] [6] In the partial structure represented by the formula (1), R １ and R ２ The compound according to any one of [1] to [4], wherein the ring structure is a six-membered ring structure containing one or two nitrogen atoms, or a five-membered ring structure containing one nitrogen atom.

[0029] [7] The compound according to [5], wherein the ring has a structure represented by any one of the following formulas (2-3) to (2-5):

[0030]

[0031] In the above formula (2-3), R ３ is R in the above formula (1) ３ The moiety corresponding to the hydrogen atom may be any substituent. The dashed line represents a bond to the metal atom.

[0032]

[0033] In the above formula (2-4), R ３ is R in the above formula (1) ３ The moiety corresponding to the hydrogen atom may be any substituent. The dashed line represents a bond to the metal atom.

[0034]

[0035] In the above formula (2-5), R ３ is R in the above formula (1) ３ The moiety corresponding to the hydrogen atom may be any substituent. The dashed line represents a bond to the metal atom.

[0036] [8] In the partial structure represented by the formula (1), R ３

[0023] The compound according to any one of [1] to [7], wherein the substituent represented by the formula: is an optionally substituted benzyl group or an optionally substituted (9-fluorenyl)methyl group.

[0037] [9] The partial structure represented by the formula (1) is the formula (1-2), and R in the formula (1-2) ３ is a (9-fluorenyl)methyl group, and R ２２ is a hydrogen atom, m is 0, and R ９ is a bond of Ar in the partial structure represented by formula (1-2), and k is 0.

[0038]

[10] The compound according to any one of [1] to [9], wherein the molecular weight of the compound is 2500 or more.

[0039]

[11] The compound according to any one of [1] to

[10] , wherein the molecular weight of the compound per partial structure represented by the formula (1) is 110 to 500.

[0040]

[12] The compound according to any one of [2] to

[11] , wherein the P block metal atom is bismuth.

[0041]

[13] The compound according to any one of [1] to

[12] , wherein the compound is a complex compound.

[0042]

[14] The compound according to

[13] , wherein 1 to 3 of the ligands are coordinated to one of the metal atoms.

[0043]

[15] A photosensitive composition comprising the compound according to any one of [1] to

[14] and an organic solvent.

[0044]

[16] A photosensitive composition comprising the compound according to any one of [1] to

[14] in a concentration of 30 to 100% by weight of the total solids.

[0045]

[17] The photosensitive composition according to

[15] or

[16] , wherein the photosensitive composition is used to form a photosensitive layer having a thickness of 50 nm on a substrate, and when predetermined regions of the photosensitive layer are irradiated with EUV light to perform pattern exposure, and the exposed photosensitive layer is developed with 4-methyl-2-pentanol, the exposed portions of the photosensitive layer are selectively removed.

[0046]

[18] A pattern formation method comprising the steps of: forming a photosensitive layer on a substrate using the photosensitive composition according to any one of

[15] to

[18] ; irradiating predetermined regions of the photosensitive layer with actinic radiation to perform pattern exposure; and developing the exposed photosensitive layer with a developer to selectively remove exposed or unexposed regions of the photosensitive layer.

[0047]

[19] The pattern forming method according to

[18] , wherein the actinic radiation has a wavelength of 6 to 15 nm.

[0048]

[20] The pattern formation method according to

[18] or

[19] , wherein the developer is an organic solvent having a solubility parameter (SP value) of 7.5 to 11.

[0049]

[21] A substrate having a patterned layer obtained by the pattern forming method according to any one of

[18] to

[20] .

[0050]

[22] A method for manufacturing a substrate in which a pattern layer is formed by the pattern formation method according to any one of

[18] to

[20] .

[0051] The present invention is suitable as a positive-working photosensitive composition, which has high sensitivity to actinic radiation exposure and is capable of forming, for example, an L&S (line and space) 1:1 pattern with a half pitch (hp) of 100 nm or 50 nm in an electron beam (EB) writing test, thereby achieving high resolution. Detailed Description of the Invention

[0052] The present invention will be described below based on one embodiment, but the present invention is not limited to this embodiment.

[0053] In addition, in this specification, there are some descriptions using "~" to indicate a numerical range from a lower limit value to an upper limit value of a numerical value, but the numerical range in this description is a numerical range specified as being equal to or greater than the lower limit value and equal to or less than the upper limit value, including the lower limit value itself and the upper limit value itself.

[0054] [Compound] A compound according to one embodiment of the present invention (hereinafter also referred to as the present compound) contains a metal atom and a ligand, and the ligand contains a partial structure represented by the following formula (1).

[0055] [In the above formula (1), R １ and R ２ are hydrogen atoms or any substituents, and may be the same or different, and may form a ring. １ , R ２ cannot be a hydrogen atom at the same time. ３ is the alpha hydrogen-containing substituent on the oxygen side of the carbamate.

[0056] The present compound is considered to be suitable for use in photolithography techniques that use extreme ultraviolet light, because it effectively absorbs EUV light with metal atoms (preferably P-block metal atoms), efficiently transfers the absorbed energy to the carbamate group, promotes decomposition of the carbamate group into carbon dioxide and an amine, and induces an accompanying change in the solubility of the photosensitive material.

[0057] Furthermore, this compound has the partial structure of the above formula (1), and has an α-hydrogen-containing substituent on the oxygen side of the carbamate group of formula (1), which promotes decomposition and elimination by EUV light. ３ Due to the high acidity of the α-hydrogen of the carbon to which R is bonded, ３ and the carboxyl oxygen atom, and the radical decomposition of the substituent induces decarboxylation of the carbamate group, resulting in the decomposition of the carbamate group, leaving only the amine, which is thought to cause a significant change in solubility. Furthermore, the decomposition of the partial structure of the above formula (1) is thought to cause a change from a high molecular weight complex compound to a low molecular weight complex compound, resulting in solubility. The α-hydrogen-containing substituent on the oxygen side of the carbamate group, in other words, is a substituent in which a hydrogen atom is substituted for the carbon bonded to the oxygen atom of the carbamate group (the α-carbon of the carbamate group). In particular, it is preferable that the α-hydrogen further corresponds to the α-hydrogen of a carbon-carbon double bond, from the viewpoint of further improving the acidity and decomposability of the α-hydrogen. Specifically, specific preferred R ３ The structure is a substituent having at least a double bond and a methylene structure adjacent thereto, and the carbon atom having the α-hydrogen of the double bond is bonded to the oxygen atom of the carbamate group of the above formula (1).

[0058] Furthermore, by converting the present compound into a repeating compound with a large molecular weight, such as an oligomer, an even greater change in solubility can be achieved. That is, while oligomers are generally known to have relatively low solubility in organic solvents, the present invention considers that by converting the compound into an oligomer, the partial structure represented by formula (1) is decomposed and eliminated by EUV light, resulting in a compound with a smaller molecular weight, thereby significantly improving solubility in organic solvents. Therefore, the present compound can achieve the effects of the present application by at least including the partial structure represented by formula (1) in its chemical structure. For example, even in cases where there are multiple types of bonds between the metal atom and the ligand, or even in cases where the compound is a repeating compound with a large molecular weight, the effects of the present application can be achieved by including the partial structure represented by formula (1).

[0059] The present compound refers to a metal complex molecule having a metal atom and a ligand, in which one or more metal atoms are bonded to each other directly or through a bridging ligand. This includes mononuclear and polynuclear complexes, and may take the form of either a complex compound or a cluster compound. The present compound is preferably a complex compound. The present compound may contain oxygen and / or hydroxyl groups within its structure, preferably a μ-oxo ligand (—O—) in which an oxygen atom is coordinated between metal atoms and / or a μ-hydroxy ligand (—OH) in which a hydroxy group is coordinated to a metal. The term cluster compound as used herein refers to a compound containing multiple metal atoms, in which the metal atoms are bonded to each other via a metal-metal bond or are bonded with one to three atoms apart. Cluster compounds containing μ-oxo ligands (—O—) and / or μ-hydroxy ligands (—OH) are sometimes referred to as oxocluster compounds.

[0060] The present compound contains a metal atom, and the metal atom may be a transition metal atom or a minor metal atom. The transition metal atom is preferably one or more selected from zirconium, hafnium, and titanium, and among these, zirconium or hafnium is preferred. Hafnium is an element in the same group as zirconium and has very similar chemical and physical properties.

[0061] The metal atom of the present compound is preferably a P-block atom. P-block metal atoms are atoms whose outermost shell is a p-orbital and are metal or metalloid atoms. Compared with transition metals, they tend to have lower melting points and boiling points, higher electronegativity, and softer materials. Examples include gallium, germanium, indium, tin, antimony, thallium, lead, bismuth, and aluminum. Among these, bismuth and antimony are preferred from the viewpoints of high absorption rate of actinic radiation and safety. Bismuth is more preferred, as it has a high mass number and a high elemental density, resulting in a high absorption rate of actinic radiation such as EUV, which is proportional to elemental density.

[0062] The present compound is preferably in an electrically neutral state, and the number of metal atoms is preferably set to be such that the compound is in an electrically neutral state. That is, the present compound is preferably not a cation or anion. Note that it may not be possible to clearly distinguish whether the present compound has a single complex structure or cluster structure, or a mixture of complex structures or cluster structures with different numbers of metal atoms.

[0063] Furthermore, the present compound may form a higher-order multimeric structure by linking together units each consisting of the above-described complex structure or cluster structure. Such multimeric structures may include dimeric to infinite complex or cluster structures. The multimeric structure may also be formed by linking each unit of the complex or cluster structure to each other via coordinate bonds of the ligands possessed by the complex or cluster structure, or by crosslinking cluster units with a linker ligand. The multimeric structure can be analyzed by known techniques, such as single-crystal X-ray crystallography.

[0064] Oxocluster compounds containing μ-oxo ligands (—O—) and / or μ-hydroxy ligands (—OH) with hydroxyl groups can also be produced by hydrolyzing the above complex compounds and cluster compounds. Specifically, water-decomposable ligands (e.g., carboxylic acid ligands, alkoxy ligands, amino ligands) exchange with water to form μ-oxo ligands (—O—) or μ-hydroxy ligands (—OH), forming an oxocluster structure. The hydrolysis reaction can be carried out by directly reacting the complex with water or water vapor, or by reacting the complex with water in any solvent. Alternatively, the complex (or a solution containing the complex) can be added to a solution containing water, causing the hydrolysis reaction to proceed, resulting in the oxocluster compound precipitating as a solid from the solution.

[0065] The ligands of this compound contain the partial structure represented by formula (1) above, and preferably 1 to 3 ligands are coordinated to one metal atom, preferably one P-block metal atom. More preferably, 2 to 3 ligands, and particularly preferably 3 ligands. Furthermore, particularly in the case of cluster compounds, the number of ligands to one P-block metal atom is preferably 0.5 to 2.5, more preferably 1.0 to 2.0. The number of ligands per metal atom can be calculated by quantifying the weight ratio of the ligand moiety contained by NMR analysis using an internal standard. It can also be calculated from the residual weight (metal content) measured by gravimetric analysis (thermogravimetry-differential thermal analysis (TG-DTA) or the like) of the residue after pyrolysis. Furthermore, the structure of the cluster can be estimated from this coordination number.

[0066] In the above formula (1), R １ or R ２ are hydrogen atoms or any substituents, which may be the same or different and may form a ring. １ , R ２ and R cannot be hydrogen atoms at the same time. １ or R ２ can be selected arbitrarily within a range that does not impair the effects of the present invention.１ or R ２ is an organic group or a halogen atom. Such an organic group may contain a halogen atom or a heteroatom. The organic group is preferably any one of a hydrocarbon group such as an alkyl group or a cycloalkyl group, an aromatic group (hereinafter also referred to as an aryl group), an ester group, a sulfonyl group, an alkoxy group, an amide group, an amino group, and a carbonyl oxygen group. １ In the structure of R, a hydrogen atom may be substituted with a halogen atom. １ or R ２ The number of carbon atoms is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3.

[0067] More specifically, examples of halogen atoms include fluorine atoms, chlorine atoms, and iodine atoms. Examples of hydrocarbon groups include alkyl groups such as methyl groups, ethyl groups, and propyl groups; halogenated alkyl groups such as halogenated methyl groups, halogenated ethyl groups, and halogenated propyl groups; cyclic alkyl groups such as cyclopropyl groups, cyclobutyl groups, cyclopentyl groups, and adamantyl groups; and (hetero)alkyl groups such as pyrrolidine groups, piperidyl groups, and piperazine groups. Examples of aromatic groups (aryl groups) include hydrocarbon-based aromatic groups such as phenyl groups and naphthyl groups; and (hetero)aryl groups such as pyridyl groups and fluorenyl groups. Examples of ester groups include alkyl ester groups such as acetyl groups, ethyl ester groups, and n-propyl ester groups; and aromatic ester groups such as phenyl ester groups. Examples of sulfonyl groups include methylsulfonyl groups, ethylsulfonyl groups, and n-propylsulfonyl groups. Examples of alkoxy groups include methoxy groups, ethoxy groups, n-propoxy groups, and phenoxy groups. Examples of amino groups include dialkylamino groups such as dimethylamino ((CH3)2N-) and diethylamino ((C2H5)2N-), and examples of amide groups include alkylamide groups such as methylamide ((CH3)2N(C=O)-) and ethylamide ((C2H5)2N(C=O)-). Other examples include carbonyl oxygen groups (>C=O).

[0068] R １ or R ２In the formula, the substituents may be bonded to each other to form a ring, and examples of such a ring include a hydrocarbon ring and a (hetero)alkyl ring, and more specifically, examples thereof include a pyrrolidine ring, a piperidine ring, and a piperazine ring. １ R is preferably a hydrocarbon group or an aromatic group, more preferably an alkyl group or an aryl group, and most preferably an alkyl group. ２ As the group, a hydrocarbon group or an aromatic group is preferable, an alkyl group or an aryl group is more preferable, and an alkyl group is even more preferable.

[0069] R in the above formula (1) ３ is an α-hydrogen-containing substituent on the oxygen side of the carbamate group, and preferably, the α-hydrogen (the α-hydrogen on the oxygen side of the carbamate group) is also an α-hydrogen of a double bond. Specific preferred substituents are either an optionally substituted 2-propenyl group or an optionally substituted arylmethylene group. This is thought to facilitate radical decomposition due to the high acidity of the α-hydrogen of the double bond upon irradiation with actinic radiation, as described below, and the radical decomposition of the substituent induces decarboxylation of the carbamate group, resulting in decomposition of the carbamate group, leaving only the amine, and causing a significant change in solubility.

[0070] R ３ The arylmethylene group in the formula (I) is a substituent bonded to the aryl structure via a methylene group. It is presumed that the presence of an α-hydrogen in the methylene group makes the above reaction more likely to occur. More specific examples of the aryl structure include a benzyl group, a (9-fluorenyl)methylene group, a naphthylmethylene group, and a nitrobenzyl group, and from the viewpoint of sensitivity, a benzyl group or a (9-fluorenyl)methylene group is preferred. The arylmethylene group preferably has 6 to 20 carbon atoms, more preferably 7 to 18, and particularly preferably 7 to 15. The 2-propenyl group is a substituent bonded to the vinyl structure via a methylene group.

[0071] These 2-propenyl groups or arylmethylene groups may further have a substituent within the range that does not impair the effects of the present invention. Specific examples of such a substituent include halogen atoms such as fluorine, chlorine, and iodine, alkyl groups such as methyl, ethyl, and propyl, halogenated alkyl groups such as halogenated methyl, ethyl, and propyl, cyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and adamantyl, and (hetero)alkyl groups such as pyrrolidine, piperidyl, and piperazine. Examples of the aromatic group (aryl group) include hydrocarbon aromatic groups such as a phenyl group and a naphthyl group; (hetero)aryl groups such as a pyridyl group and a fluorenyl group; amino groups such as an alkylamino group, an aralkylamino group, and an arylamino group; carbonyl groups such as an alkylcarbonyl group, an aralkylcarbonyl group, and an arylcarbonyl group; ester groups such as an alkyloxycarbonyl group, an aralkyloxycarbonyl group, and an aryloxycarbonyl group; carbamate groups such as an alkyloxycarbonylamino group, an aralkyloxycarbonylamino group, and an aryloxycarbonylamino group; and a nitro group.

[0072] The number of carbon atoms in the 2-propenyl group which may have a substituent is preferably 1 to 10, more preferably 1 to 8, and particularly preferably 1 to 5. The number of carbon atoms in the arylmethylene group which may have a substituent is preferably 6 to 30, more preferably 7 to 25, and particularly preferably 7 to 20.

[0073] The partial structure represented by the formula (1) in the present compound is preferably either A) a ligand having an aryl group or B) a ligand having a ring structure containing nitrogen.

[0074] A) The ligand having an aryl group is preferably, for example, represented by the following formula (1-1) or (1-2).

[0075]

[0076] In the above formula (1-1), Ar is an aryl group, and R １６ ~R １９are each independently a hydrogen atom or an arbitrary substituent, and may be the same or different. １６ ~R １９ The optional substituents of R are organic groups or halogen atoms, and such organic groups may contain halogen atoms or heteroatoms. １ and R １６ ~R １９ Each of R is preferably a hydrocarbon group such as a methyl group or an adamantyl group. １６ ~R １９ The number of carbon atoms is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3.

[0077] Examples of the aryl group include hydrocarbon aromatic groups such as a phenyl group and a naphthyl group, (hetero)aryl groups such as a pyridyl group and a fluorenyl group, amino groups such as an alkylamino group, an aralkylamino group and an arylamino group, carbonyl groups such as an alkylcarbonyl group, an aralkylcarbonyl group and an arylcarbonyl group, ester groups such as an alkyloxycarbonyl group, an aralkyloxycarbonyl group and an aryloxycarbonyl group, carbamate groups such as an alkyloxycarbonylamino group, an aralkyloxycarbonylamino group and an aryloxycarbonylamino group, and a nitro group. 16 is a hydrogen atom, and R 17 is an adamantylcarbamine group, and R 18 is an adamantyl group, and R 19 is a hydrogen atom.

[0078]

[0079] In the above formula (1-2), R ３ is R in the above formula (1). ３ It is. ２０ ~R ２２ are each independently a hydrogen atom or an arbitrary substituent, and may be the same or different. ２０ ~R ２２The optional substituents of R are organic groups or halogen atoms, and such organic groups may contain halogen atoms or heteroatoms. For example, R １ and R ２０ ~R ２２ are each preferably a hydrocarbon group such as a methyl group or an adamantyl group. ２０ ~R ２２ The number of carbon atoms in each of the groups is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3. In the above formula (1-2), m is 0 or an integer of 1 or more, preferably 0 to 10, and more preferably 0 to 4.

[0080] Examples of the aryl group include the following formula (2-1) or (2-2).

[0081]

[0082] In the above formula (2-1), R ４ ~R ８ are each independently a hydrogen atom or any substituent, and may be the same or different; R ４ ~R ８ At least one of the substituents is a bond of Ar in the partial structure represented by the above formula (1-1) or (1-2). ４ ~R ８ The substituent of R is an organic group or a halogen atom, and the organic group may contain a halogen atom or a hetero atom. １ and R ４ ~R ８ Each of R is preferably a hydrocarbon group, more preferably an alkyl group or an aryl group. ４ ~R ８ The number of carbon atoms in each of the groups is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3. The dashed line represents a bond to a metal atom.

[0083]

[0084] In the above formula (2-2), R ９ ~R １５are each independently a hydrogen atom or an arbitrary substituent, and may be the same or different; R ９ ~R １３ At least one of the substituents is a bond to Ar in the partial structure represented by the above formula (1-1) or (1-2). ９ ~R １５ The substituent of is an organic group or a halogen atom, and the organic group may contain a halogen atom or a hetero atom. For example, １ and R ９ ~R １５ Each of R is preferably a hydrocarbon group, more preferably an alkyl group or an aryl group. ９ ~R １５ The number of carbon atoms in each of R is preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3. The dashed line represents a bond to a metal atom. １４ , R １５ is preferably hydrogen. In the formula (2-2), k is 0 or an integer of 1 or more, preferably 0 to 10, and more preferably 0 to 4.

[0085] B) As the ligand having a ring structure containing nitrogen, preferably, in the partial structure represented by the formula (1), R １ and R ２ Furthermore, in the partial structure represented by the formula (1), R １ and R ２ However, compounds forming a six-membered ring structure containing one or two nitrogen atoms or a five-membered ring structure containing one nitrogen atom are preferred. Examples of the six-membered ring structure or the five-membered ring structure in the ligand having such a six-membered ring structure containing one or two nitrogen atoms or a five-membered ring structure containing one nitrogen atom include any of the following structures (2-3) to (2-5).

[0086]

[0087] In the above formula (2-3), R ３ is R in the above formula (1) ３The portion corresponding to the hydrogen atom may be an arbitrary substituent. Examples of the arbitrary substituent include the above-mentioned R １ The substituents are preferably alkyl groups. The broken lines represent bonds to metal atoms.

[0088]

[0089] In the above formula (2-4), R ３ is R in the above formula (1) ３ The portion corresponding to the hydrogen atom may be an arbitrary substituent. Examples of the arbitrary substituent include the above-mentioned R １ The substituents are preferably alkyl groups. The broken lines represent bonds to metal atoms.

[0090]

[0091] In the above formula (2-5), R ３ is R in the above formula (1) ３ The portion corresponding to the hydrogen atom may be an arbitrary substituent. Examples of the arbitrary substituent include the above-mentioned R １ The substituents are preferably alkyl groups. The broken lines represent bonds to metal atoms.

[0092] Among these, a suitable example of the ligand of the present compound is a compound in which the partial structure represented by the formula (1) is the formula (1-2), and R ３ is a (9-fluorenyl)methyl group, and R ２２ is a hydrogen atom, m is 0, Ar is a group represented by formula (2-2), and the substituent R ９ is a bond to Ar in the partial structure represented by the formula (1-2), and k is 0.

[0093] The structure of the ligand of the present compound can be analyzed by known techniques, for example, by NMR or MASS measurement.

[0094] The molecular weight of the compound is preferably 2,500 or more, more preferably 3,000 or more, and particularly preferably 3,500 or more. From the viewpoint of stability of a composition mixed with an organic solvent, the molecular weight is preferably 20,000 or less, and from the viewpoint of solubility, the molecular weight is more preferably 15,000 or less, and even more preferably 10,000 or less.

[0095] In the case of a mononuclear complex (a complex compound having one metal atom in one molecule), the molecular weight is preferably 150 or more, more preferably 200 or more, and more preferably 300 or more, in view of the balance between the weight of the metal and the ligand. From the viewpoint of solubility, the molecular weight is preferably 1500 or less, more preferably 1000 or less, and more preferably 800 or less.

[0096] When the compound is a cluster compound, its molecular weight is preferably 2,000 or more, more preferably 2,500 or more, and particularly preferably 3,000 or more. From the viewpoint of the stability of the composition mixed with an organic solvent, a molecular weight of 20,000 or less is preferred. From the viewpoint of solubility, a molecular weight of 15,000 or less is more preferred, and a molecular weight of 10,000 or less is even more preferred. From the viewpoint of the molecular volume required for fine patterning, a molecular weight of 6,000 or less is preferred. If the molecular weight of the compound is below the above upper limit, the volume is small, and therefore roughness and resolution are expected to be improved. Note that this molecular weight is a guideline and does not determine the lithography properties by itself, so it is not limited to this. The compound can also be made into a compound with a large molecular weight, such as an oligomer, which can cause a significant change in solubility. Furthermore, mononuclear complexes have a small molecular weight, which is preferable in that the molecular size is small and roughness is reduced in fine patterning. Cluster compounds contain multiple metal atoms, which not only provide high sensitivity, but also have a high molecular weight, which allows for a large change in solubility before and after exposure, thereby providing a large solubility contrast as a resist material.

[0097] In addition, the present compound preferably has a molecular weight of 110 to 500, more preferably 110 to 450, and particularly preferably 110 to 400 per partial structure represented by the above formula (1).

[0098] The molecular weight of the present compound can be analyzed by known methods, for example, by NMR or MASS.

[0099] This compound is advantageous in that its structure changes or decomposes upon exposure, resulting in a significant change in its solubility as a resist film. The structural change in the resist film can be analyzed by analyzing the composition of the film before and after exposure. For example, the change can be confirmed by analyzing the ratio of the ligand component to the metal component through composition analysis of the film by XPS.

[0100] [Method for Producing the Present Compound] The present compound can be produced, for example, by reacting a phenyl compound of a metal atom with a carboxylic acid containing the partial structure represented by formula (1) above. More specifically, for example, a phenyl compound of a metal atom and a carboxylic acid derivative having a protonated structure represented by general formula (2-2) above are placed in a reaction vessel and refluxed in toluene for a long period of time. The reflux stirring time is preferably 1 to 48 hours, more preferably 4 to 48 hours. A sealed vessel is desirable as the reaction vessel, and if the volume is small, a Schlenk tube or the like can be used, and the reaction is preferably carried out under a nitrogen or argon atmosphere.

[0101] Alternatively, the compound can be produced by synthesizing a phenyl compound of a metal atom and then introducing optional substituents using organic synthesis techniques. More specifically, for example, the compound represented by formula (2-1) above can be obtained by preparing a Grignard reagent of O-TMS-modified 4-bromobenzyl alcohol, reacting it with bismuth chloride, deprotecting the TMS, and then reacting the resulting trialcohol bismuth complex with an isocyanate compound. Furthermore, a compound having a bismuth compound linked thereto can also be synthesized by reacting a trialcohol bismuth complex with a diisocyanate compound. Furthermore, the compound can be synthesized by using a metal complex having, for example, an alkoxy ligand, a carboxylic acid ligand, an amino ligand, or a halogen ligand as a raw material, and exchanging the ligand (the ligand in the raw material complex) with the desired ligand. Specifically, the synthesis method involves dissolving or dispersing the raw material metal complex in a solvent and mixing in a more reactive ligand. In addition, during the exchange reaction, procedures such as heating, reducing pressure, distillation, and crystallization can be used to remove or decompose the ligands in the raw materials, which can accelerate the reaction and produce a target product of higher purity.

[0102] The temperature for storing the present compound is preferably room temperature, specifically, preferably 15 to 40°C, more preferably 20 to 30°C.

[0103] Examples of phenyl compounds of metal atoms used in the production of the present compound include triphenylbismuth, tris(p-tolyl)bismuth, etc. Examples of carboxylic acids containing the partial structure represented by the above formula (1) used in the production of the present compound include (S)—N-(9-fluorenylmethoxycarbonyl)piperidine-2-carboxylic acid and N-(benzyloxycarbonyl)piperidine-2-carboxylic acid.

[0104] In producing the present compound, the phenyl compound of a metal atom and the carboxylic acid containing the partial structure represented by the above formula (1) are preferably mixed in a substance ratio of 1:1 to 1:3, more preferably 1:3.

[0105] While no specific manufacturing method is required for cluster compounds, they can be synthesized as complex compounds containing multiple metals by addition or condensation reactions using metal complexes as raw materials. For example, they can be produced by using metal complexes containing alkoxy, carboxylic acid, amino, or halogen ligands as raw materials, forming clusters of the ligands (the ligands in the raw material complex) and exchanging them for bridging ligands. For example, when water is used, a hydrolysis reaction occurs, resulting in the synthesis of oxocluster compounds containing μ-oxo ligands (—O—) and / or μ-hydroxy ligands (—OH). While there are no particular limitations on the method for reacting the raw material complex compound with water to obtain these oxocluster compounds, a preferred method involves adding the raw material complex compound dissolved in a solvent dropwise to a water-containing solvent. This method is advantageous because it allows the reaction between water and the complex to proceed under mild conditions, and the resulting cluster compound can be precipitated (reprecipitated) as a solid and then filtered off to produce the desired cluster compound with high purity.

[0106] [Photosensitive Composition] A photosensitive composition according to one embodiment of the present invention (hereinafter also referred to as the present photosensitive composition) contains the present compound. The present photosensitive composition may contain only one type of the present compound, or two or more types. Furthermore, the present photosensitive composition may contain additives such as polymeric compounds such as urethane polymers and acrylic polymers, agents that assist structural changes upon exposure, and stabilizers in solution, as long as the effects of the present invention are not impaired. The content of the present compound in the present photosensitive composition is 30 to 100% by mass, preferably 40 to 100% by mass, and particularly preferably 50 to 100% by mass, based on the total solid content of the photosensitive composition. The term "total solid content" refers to the solid obtained by evaporating the photosensitive composition to dryness. The concentration of the present compound in the present photosensitive composition is preferably 0.1% by mass or more and 70% by mass or less, more preferably 0.5% by mass or more and 50% by mass or less, and particularly preferably 1% by mass or more and 40% by mass or less. When the content of the present compound in the present photosensitive composition is equal to or greater than the above lower limit, good exposure sensitivity can be obtained.

[0107] The present photosensitive composition is suitable as a positive resist. For example, the present photosensitive composition is used to form a photosensitive layer having a thickness of 50 nm (acceptable range: 46 to 54 nm) on a substrate, and predetermined regions of the photosensitive layer are irradiated with EUV light for pattern exposure. The exposed photosensitive layer is then developed with 4-methyl-2-pentanol, whereby the exposed portions of the photosensitive layer are selectively removed, thereby enabling the effects of the present application to be more efficiently achieved.

[0108] [Photoacid Generator] The photosensitive composition can also function by containing, together with the compound, a photoacid generator that generates an acid when exposed to actinic radiation. Examples of actinic radiation include the bright line spectrum of a mercury lamp, far ultraviolet radiation represented by an excimer laser, extreme ultraviolet radiation (EUV light), X-rays, and electron beams. From the viewpoint of resolution, a shorter exposure wavelength is preferred, and extreme ultraviolet radiation (EUV light) emitting light with a wavelength of 6 nm to 15 nm is preferred.

[0109] The photoacid generator that generates an acid when exposed to actinic radiation is not particularly limited as long as it is a known compound, but is preferably a compound that generates an organic acid, such as at least one of sulfonic acid, bis(alkylsulfonyl)imide, and tris(alkylsulfonyl)methide, when exposed to actinic radiation.

[0110] The photoacid generators can be used alone or in combination of two or more. When two or more types are used in combination, preferred embodiments include (1) the use of two photoacid generators with different acid strengths, and (2) the use of two photoacid generators with different sizes (molecular weights or carbon numbers) of the acids they generate. Examples of the embodiment (1) include the use of a fluorine-containing sulfonic acid generator and a tris(fluoroalkylsulfonyl)methide acid generator, a fluorine-containing sulfonic acid generator and a non-fluorine-containing sulfonic acid generator, and an alkylsulfonic acid generator and an arylsulfonic acid generator. Examples of the embodiment (2) include the use of two photoacid generators whose acid anions differ in the number of carbon atoms by four or more.

[0111] In particular, the present photosensitive composition is preferably a photosensitive composition for use with actinic radiation. A photosensitive composition that reacts with actinic radiation is preferred because its development speed in a developer changes, allowing a pattern to be formed after a certain period of development. As actinic radiation, a shorter wavelength is preferred because higher resolution can be obtained, and actinic radiation with a wavelength of 6 nm to 15 nm is preferred, and more preferably actinic radiation with a wavelength of 6.5 nm to 13.5 nm is preferred. In other words, extreme ultraviolet (EUV) light is preferred. In other words, the present photosensitive composition is preferably a photosensitive composition that reacts with actinic radiation with a wavelength of 6 nm to 15 nm. "Reaction" refers to the photosensitive composition absorbing the irradiated actinic radiation and then being modified by the generated active species, such as radicals and ions.

[0112] The present photosensitive composition reacts with light even when used alone in the photosensitive composition. Adding a photoacid generator synergistically enhances photosensitivity with the present compound in the photosensitive composition, thereby enhancing the photosensitivity of the present compound. Therefore, adding a photoacid generator is preferable when a photosensitive composition composed solely of the present compound does not have sufficient photosensitivity for the required specifications. When the present photosensitive composition contains a photoacid generator, the content of the photoacid generator in the present photosensitive composition (the total amount when multiple photoacid generators are used) is preferably 0.1 to 30% by mass, more preferably 0.5 to 20% by mass, and even more preferably 1 to 15% by mass, based on the total components of the photosensitive composition other than the solvent. When the content of the photoacid generator in the photosensitive composition is at or above the lower limit, the effect of enhancing photosensitivity is obtained. When the content is at or below the upper limit, the composition is less susceptible to the poor film-forming properties of the photoacid generator, thereby achieving good film-forming properties based on the photosensitive compound of the present invention, which is preferable.

[0113] [Solvent] The present photosensitive composition usually contains a solvent for preparing the composition. The solvent for preparing the photosensitive composition is not particularly limited as long as it dissolves each component, and examples thereof include toluene, alkylene glycol monoalkyl ether carboxylates (such as propylene glycol monomethyl ether acetate (PGMEA, also known as 1-methoxy-2-acetoxypropane)), alkylene glycol monoalkyl ethers (such as propylene glycol monomethyl ether (PGME; 1-methoxy-2-propanol)), alkyl lactate esters (such as ethyl lactate and methyl lactate), cyclic lactones (such as γ-butyrolactone, preferably having 4 to 10 carbon atoms), linear or cyclic ketones (such as 2-heptanone and cyclohexanone, preferably having 4 to 10 carbon atoms), alkylene carbonates (such as ethylene carbonate and propylene carbonate), alkyl carboxylates (preferably alkyl acetates such as butyl acetate), alkyl alkoxyacetates (ethyl ethoxypropionate), alkylamides (N,N-dimethylformamide), and alkyl sulfoxides (dimethyl sulfoxide). Other usable solvents include, for example, the solvents described in paragraphs

[0244] and after of US Patent Application Publication No. 2008 / 0248425A1.

[0114] Of the above, toluene, PGMEA, ethyl lactate, cyclohexanone, cyclopentanone, 2-heptanone, N,N-dimethylformamide, dimethyl sulfoxide, alkylene glycol monoalkyl ether carboxylate, and alkylene glycol monoalkyl ether are preferred.

[0115] These solvents may be used alone or in combination of two or more. When two or more solvents are mixed, it is preferable to mix a solvent having a hydroxyl group with a solvent not having a hydroxyl group. As the solvent having a hydroxyl group, alkylene glycol monoalkyl ether is preferred, and as the solvent not having a hydroxyl group, alkylene glycol monoalkyl ether carboxylate, N,N-dimethylformamide, and dimethyl sulfoxide are preferred.

[0116] The solvent for the present photosensitive composition preferably has a solubility parameter (SP value) of 7.5 to 11, more preferably 8 to 11. The solubility parameter (SP value) will be described later.

[0117] The content of the solvent in the total amount of the photosensitive composition can be adjusted as appropriate depending on the film thickness of the pattern to be formed, etc., but is generally adjusted so that the total concentration of components other than the solvent in the photosensitive composition is 0.5 to 30 mass %, preferably 1.0 to 20 mass %, more preferably 1.5 to 10 mass %, and particularly preferably 1.5 to 5 mass %.

[0118] [Surfactant] The photosensitive composition preferably further contains a surfactant. The surfactant is preferably a fluorine-based and / or silicone-based surfactant. Examples of such surfactants include Megafac F176 and Megafac R08 manufactured by Dainippon Ink and Chemicals, Inc., PF656 and PF6320 manufactured by OMNOVA, Troisol S-366 manufactured by Troy Chemical Co., Ltd., Fluorad FC430 manufactured by Sumitomo 3M Limited, and Polysiloxane Polymer KP-341 manufactured by Shin-Etsu Chemical Co., Ltd. Surfactants other than fluorine-based and / or silicone-based surfactants can also be used. More specifically, examples include polyoxyethylene alkyl ethers and polyoxyethylene alkylaryl ethers.

[0119] Other known surfactants may also be used as appropriate, such as those described in U.S. Patent Application Publication No. 2008 / 0248425A1, paragraphs

[0273] and thereafter.

[0120] The surfactant may be used alone or in combination of two or more kinds. The content of the surfactant is preferably 0.0001 to 2 mass %, more preferably 0.001 to 1 mass %, based on the total mass of the components other than the solvent in the photosensitive composition.

[0121] [Resin] The photosensitive composition can be used alone to form a pattern, but it may also contain a resin material in addition to the compound. Resin materials are not particularly limited as long as they are soluble in a solvent, and examples include novolac resins, styrene resins, and acrylic resins. They may be used alone or in combination of two or more types. Their molecular structure may contain dissolution-inhibiting groups that decompose in the presence of chemically active species such as acids or radicals, or crosslinking groups that crosslink, or they may be copolymer resins of two or more types. Examples of dissolution-inhibiting groups that decompose in the presence of chemically active species such as acids or radicals include alkoxycarbonyl groups and acetal groups. Examples of crosslinking groups that crosslink in the presence of chemically active species such as acids or radicals include vinyl groups, carbodiimide groups, N-hydroxyester groups, imide ester groups, maleimide groups, haloacetyl groups, pyridyl disulfide groups, hydrazide groups, alkoxyamino groups, and diazirine groups.

[0122] [Other Additives] In addition to the components described above, the photosensitive composition may contain, as appropriate, carboxylic acids, carboxylic acid onium salts, dissolution-inhibiting compounds with a molecular weight of 3,000 or less as described in, for example, Proceedings of SPIE, 2724, 355 (1996), dyes, plasticizers, photosensitizers, light absorbers, crosslinking agents, antioxidants, and the like. Carboxylic acids are particularly preferred for improving performance. Preferred carboxylic acids include aromatic carboxylic acids such as benzoic acid and naphthoic acid. The carboxylic acid content is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and even more preferably 0.01 to 3% by mass, based on the total weight of the components of the photosensitive composition other than the solvent.

[0123] [Method for producing the present photosensitive composition] The present photosensitive composition can be produced by dissolving the present compound, a photoacid generator (if used) and other components in a solvent for preparation, and filtering the solution through a filter, if necessary. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon, and has a pore size of 0.2 μm or less, more preferably 0.1 μm or less, and even more preferably 0.05 μm or less.

[0124] [Pattern Forming Method] A pattern forming method according to one embodiment of the present invention (hereinafter also referred to as the present pattern forming method) comprises the steps of applying the present photosensitive composition to a substrate, exposing to actinic radiation, and developing. More specifically, it comprises the steps of applying the present photosensitive composition to a substrate to form a photosensitive layer, irradiating predetermined regions of the photosensitive layer with actinic radiation to perform pattern exposure, and developing the exposed photosensitive layer to selectively remove exposed or unexposed regions of the photosensitive layer. The photosensitive layer forming step provides a substrate having a photosensitive layer. The pattern exposure step provides a substrate with a latent image. The development step provides a substrate having a pattern layer.

[0125] [Photosensitive Layer Formation Step] The photosensitive layer can be formed by applying the photosensitive composition to a substrate (e.g., silicon or silicon dioxide coated) such as those used in the manufacture of integrated circuit devices using a suitable coating method such as a spinner, followed by drying at 50 to 150°C. In this case, a commercially available inorganic or organic antireflective film can be used, if necessary. Furthermore, an antireflective film can be applied as an underlayer of the resist.

[0126] [Exposure Step] In the present invention, unless otherwise specified, "exposure to actinic radiation" includes not only exposure with far ultraviolet light typified by mercury lamps and excimer lasers, X-rays, extreme ultraviolet light (EUV light), and the like, but also exposure with particle beams such as electron beams and ion beams. Exposure can be performed by irradiating predetermined regions of the formed photosensitive layer with actinic radiation through a predetermined mask to perform pattern exposure, or by irradiating with an electron beam to perform pattern exposure without using a mask (direct writing). The actinic radiation is not particularly limited, but examples include KrF excimer lasers, ArF excimer lasers, extreme ultraviolet light (EUV light), and electron beams. Extreme ultraviolet light (EUV light) and electron beams are preferred, and as described above, extreme ultraviolet light (EUV light) emitting actinic radiation with a wavelength of 6 nm to 15 nm is preferred.

[0127] After the exposure, baking (heating) may or may not be performed before development. When baking (heating) is performed, the heating temperature is preferably 50 to 200°C, more preferably 60 to 180°C, and even more preferably 80 to 150°C. When baking (heating) is performed, the heating time is preferably 30 to 300 seconds, more preferably 30 to 180 seconds, and even more preferably 30 to 90 seconds. Heating can be performed by means provided in a normal exposure / developing machine, and may be performed using a hot plate or the like.

[0128] [Development Step] After exposure, development is carried out to selectively remove the exposed or unexposed areas of the photosensitive layer. As the development method, a known method can be adopted, for example, a method using a gas or a method using a developer.

[0129] <Developer> It is preferable to use an organic solvent as the developer, and an organic solvent having a vapor pressure of 5 kPa or less at 20° C. is preferred, more preferably 3 kPa or less, and particularly preferably 2 kPa or less. By setting the vapor pressure of the organic solvent to 5 kPa or less, evaporation of the developer on the substrate or in the developing cup is suppressed, improving the temperature uniformity within the surface of the pattern-formed substrate, and as a result, improving the dimensional uniformity within the surface of the pattern-formed substrate.

[0130] As the organic solvent used as the developer, various organic solvents can be used, and for example, at least one solvent selected from ester-based solvents, ketone-based solvents, alcohol-based solvents, amide-based solvents, sulfoxide-based solvents, ether-based solvents, hydrocarbon-based solvents, and the like can be used.

[0131] Examples of ester-based solvents include alkyl carboxylate solvents such as methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, ethyl-3-ethoxypropionate, propylene glycol diacetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, and propyl lactate; alkylene glycol monoalkyl ether carboxylate solvents such as propylene glycol monomethyl ether acetate (PGMEA; also known as 1-methoxy-2-acetoxypropane), ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, and propylene glycol monoethyl ether acetate; and butyl acetate, amyl acetate, ethyl lactate, and propylene glycol monomethyl ether acetate are more preferred.

[0132] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl amyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, and propylene carbonate. Alkyl ketone solvents, such as methyl isobutyl ketone, methyl amyl ketone, cyclopentanone, cyclohexanone, and 2-heptanone, are more preferred.

[0133] Examples of alcohol-based solvents include alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol including 1-propanol or 2-propanol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, hexyl alcohols such as n-hexyl alcohol, heptyl alcohols such as n-heptyl alcohol, octyl alcohols such as n-octyl alcohol, and n-decanol; and glycols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, and 1,4-butylene glycol. alkylene glycol monoalkyl ether-based solvents such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether (PGME; also known as 1-methoxy-2-propanol), ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monomethyl ether, and triethylene glycol monoethyl ether; glycol ether-based solvents such as methoxymethylbutanol and propylene glycol dimethyl ether; and phenol-based solvents such as phenol and cresol, with 1-hexanol, 2-hexanol, 1-octanol, 2-ethylhexanol, propylene glycol monomethyl ether, and cresol being more preferred.

[0134] Examples of the amide solvent that can be used include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone, etc. Examples of the sulfoxide solvent that can be used include dimethyl sulfoxide, etc.

[0135] Examples of the ether solvent include the alkylene glycol monoalkyl ether solvents and glycol ether solvents described above, as well as dioxane, tetrahydrofuran, tetrahydropyran, and the like.

[0136] Examples of hydrocarbon solvents include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as pentane, hexane, octane, decane, and dodecane.

[0137] The developer preferably contains one or more solvents selected from alkylene glycol monoalkyl ether carboxylate solvents, alkylene glycol monoalkyl ether solvents, alkyl carboxylate solvents, and alkyl ketone solvents, and more preferably contains one or more solvents selected from dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, ethylene glycol, methyl alcohol, ethyl alcohol, 1-propanol, and 2-propanol.

[0138] As the developer, it is preferable to use a developer containing at least one organic solvent selected from the group consisting of ester solvents having no hydroxyl group in the molecule, ketone solvents having no hydroxyl group in the molecule, and ether solvents having no hydroxyl group in the molecule, amide solvents, and sulfoxide solvents.

[0139] The organic solvent used as the developer in the present invention is preferably an organic solvent having a solubility parameter (SP value) of 7.5 to 11. An organic solvent with a solubility parameter of 7.5 or more increases the development rate of the dissolved portion, while an organic solvent with a solubility parameter of 11 or less can suppress the development rate of the pattern formation portion, and is therefore preferred. The solubility parameter of the organic solvent of the developer is more preferably 8 to 11.

[0140] In the present invention, the solubility parameter (SP value) is calculated by the method proposed by Fedors et al. Specifically, the value is determined by referring to "POLYMER ENGINEERING AND SCIENCE, FEBRUARY, 1974, Vol. 14, No. 2, ROBERT F. FEDORS. (pp. 147-154)." The SP value is a physical property determined by the content of hydrophobic and hydrophilic groups in the molecule, and when a mixed solvent is used, the SP value refers to the value of the mixture.

[0141] Examples of organic solvents that satisfy the above SP values ​​include diethylene glycol monomethyl ether (SP value = 10.7), triethylene glycol monomethyl ether (SP value = 10.7), ethylene glycol monoisopropyl ether (SP value = 10.9), ethylene glycol monobutyl ether (SP value = 10.2), diethylene glycol monobutyl ether (SP value = 10.0), triethylene glycol monobutyl ether (SP value = 10.0), ethylene glycol monoisobutyl ether (SP value = 9.1), ethylene glycol monohexyl ether (SP value = 9.9), diethylene glycol monohexyl ether (SP value = 9.7), diethylene glycol mono-2-ethylhexyl ether (SP value = 9.3), ethylene glycol monoallyl ether (SP value = 10.8), ethylene glycol monophenyl ether (SP value = 10.8), ethylene glycol monobenzyl ether (SP value = 10.9), propylene glycol monomethyl ether (SP value = 10.0), dipropylene glycol monomethyl ether (SP value = 10.0), and dipropylene glycol monomethyl ether (SP value = 10.0). propylene glycol monomethyl ether (SP value = 9.7), tripropylene glycol monomethyl ether (SP value = 9.4), propylene glycol monopropyl ether (SP value = 9.6), dipropylene glycol monopropyl ether (SP value = 9.8), propylene glycol monobutyl ether (SP value = 9.0), dipropylene glycol monobutyl ether (SP value = 9.6), ethylene glycol monomethyl ether acetate (SP value = 10.0), ethylene glycol monoethyl ether acetate ether acetate (SP value = 9.6), ethylene glycol monobutyl ether acetate (SP value = 8.9), diethylene glycol monoethyl ether acetate (SP value = 9.4), diethylene glycol monobutyl ether acetate (SP value = 9.0), propylene glycol monomethyl ether acetate (SP value = 9.4), propylene glycol monoethyl ether acetate (SP value = 9.0), and dipropylene glycol monomethyl ether acetate (SP value = 9.2).

[0142] The organic solvents may be used in combination with a plurality of solvents, or may be used in combination with other solvents or water. For example, as described in WO 2020 / 210660, at least two solvents each independently having a Hansen solubility parameter δH + δP of about 16 (J / cm ３ ) 1 / 2 or less, each independently having a sum of Hansen solubility parameters δH + δP of at least about 16 (J / cm ３ ) 1 / 2, it is also possible to use developer compositions that include from about 0.25% to about 45% by volume of one or more solvents.

[0143] The concentration of the organic solvent (total when a plurality of organic solvents are mixed) in the developer is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. It is particularly preferred that the developer essentially consists of an organic solvent. The term "essentially consisting of an organic solvent" includes the case where the developer contains trace amounts of a surfactant, an antioxidant, a stabilizer, an antifoaming agent, etc.

[0144] The water content in the developer is preferably 10% by mass or less, more preferably 5% by mass or less, particularly preferably 3% by mass or less, and most preferably substantially no water. By keeping the water content at 10% by mass or less, good development characteristics can be obtained.

[0145] If necessary, an appropriate amount of a surfactant can be added to the developer used in the present invention. The surfactant may be the same as those described above as surfactants used in the photosensitive composition of the present invention. The amount of the surfactant used is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, based on the total amount of the developer.

[0146] <Development Method> Examples of development methods that can be used include a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which a developer is piled up on the surface of a substrate by surface tension and left standing for a certain period of time (puddle method), a method in which a developer is sprayed onto the surface of the substrate (spray method), and a method in which a developer is continuously dispensed onto a substrate rotating at a constant speed while a developer dispenser nozzle is scanned at a constant speed (dynamic dispense method). Furthermore, after the development step, a step of stopping development by replacing the solvent with another solvent may be carried out. The development time is preferably a time required for the present compound and the like in the photosensitive layer in the unexposed or exposed areas to be sufficiently dissolved, and is usually preferably 10 to 300 seconds, more preferably 20 to 120 seconds. The temperature of the developer is preferably 0 to 50°C, more preferably 15 to 35°C. The amount of developer can be appropriately adjusted depending on the development method.

[0147] [Rinsing Step] The pattern forming method of the present invention may include, after the developing step, a step of washing with a rinse liquid containing an organic solvent.

[0148] <Rinse Liquid> The organic solvent used in the rinse liquid preferably has a vapor pressure of 0.05 kPa or more and 5 kPa or less, more preferably 0.1 kPa or more and 5 kPa or less, and most preferably 0.12 kPa or more and 3 kPa or less at 20° C. By adjusting the vapor pressure of the organic solvent used in the rinse liquid to 0.05 kPa or more and 5 kPa or less, the temperature uniformity within the wafer surface is improved, and further swelling due to penetration of the rinse liquid is suppressed, improving the dimensional uniformity within the wafer surface.

[0149] Various organic solvents can be used as the rinse solution. For the present compound, it is preferable to use a rinse solution containing at least one organic solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents, or water. More preferably, after development, a cleaning step is performed using a rinse solution containing at least one organic solvent selected from ketone solvents, ester solvents, alcohol solvents, amide solvents, and hydrocarbon solvents. Even more preferably, after development, a cleaning step is performed using a rinse solution containing at least one organic solvent selected from the group consisting of alcohol solvents and hydrocarbon solvents. For example, as described in WO 2020 / 081483, a method can be used in which the rinse solution contains a quaternary ammonium hydroxide aqueous solution and the developer solution contains an organic solvent, or a method can be used in which the developer solution contains a quaternary ammonium hydroxide aqueous solution and the rinse solution contains an organic solvent. Specific examples of the ketone-based solvent, ester-based solvent, alcohol-based solvent, amide-based solvent, ether-based solvent, and hydrocarbon-based solvent used as the rinse solution are the same as those described above for the developer. Particularly preferably, a rinse solution containing at least one organic solvent selected from the group consisting of monohydric alcohol-based solvents, hydrocarbon-based solvents, and amide-based solvents is used.

[0150] Here, examples of the monohydric alcohol solvent used in the rinsing step after development include linear, branched, and cyclic monohydric alcohols. Specific examples include 1-butanol, 2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, isopropyl alcohol, cyclopentanol, and cyclohexanol, with 1-butanol, 2-butanol, 3-methyl-1-butanol, and isopropyl alcohol being preferred. Examples of the hydrocarbon solvent include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as octane, decane, and dodecane. Examples of the amide solvent include N,N-dimethylformamide.

[0151] The above-mentioned components may be mixed in plural, or may be mixed with an organic solvent other than those mentioned above.

[0152] The organic solvent may be mixed with water, but the water content in the rinse solution is usually 30% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. Most preferably, the rinse solution does not contain water. By keeping the water content at 30% by mass or less, good development properties can be obtained.

[0153] The rinse solution may contain an appropriate amount of a surfactant, which may be the same as those used in the photosensitive composition described above, and the amount of surfactant used is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the rinse solution.

[0154] <Rinsing Method> In the rinsing step, the developed pattern-formed substrate is washed with a rinse solution containing the organic solvent. The washing method is not particularly limited, but examples include a method in which the rinse solution is continuously applied to a substrate rotating at a constant speed (spin coating method), a method in which the substrate is immersed in a tank filled with the rinse solution for a certain period of time (dipping method), and a method in which the rinse solution is sprayed onto the substrate surface (spray method). Among these, the spin coating method is preferred for washing, and after washing, the substrate is rotated at a speed of 2000 to 4000 rpm to remove the rinse solution from the substrate. The substrate rotation time can be set depending on the rotation speed within a range that achieves removal of the rinse solution from the substrate, but is typically 10 seconds to 3 minutes. Rinsing is preferably performed at room temperature. The rinse time is preferably set so that no developing solvent remains on the substrate, typically 10 to 300 seconds, more preferably 20 to 120 seconds. The temperature of the rinse solution is preferably 0 to 50°C, and even more preferably 15 to 35°C. The amount of the rinse solution can be adjusted appropriately depending on the rinse method.

[0155] [Post-treatment Step] After the development treatment or rinsing treatment, a treatment can be performed using a supercritical fluid to remove the developer or rinsing solution adhering to the pattern. Furthermore, after the development treatment, rinsing treatment, or treatment with a supercritical fluid, a heat treatment can be performed to remove the solvent remaining in the pattern. The heating temperature and time are not particularly limited as long as a good resist pattern can be obtained, and are usually 40 to 160°C and 10 seconds to 3 minutes. The heat treatment may be performed multiple times.

[0156] [Uses] The present compound is suitable as a positive-type photosensitive composition and is suitably used in the production of semiconductor microcircuits, such as in the production of VLSIs and high-capacity microchips, and a substrate having a patterned layer can be produced by the present pattern formation method using the present photosensitive composition. Note that when producing semiconductor microcircuits, the resist film on which the pattern is formed is subjected to circuit formation and etching, and the remaining resist film portion is eventually removed with a solvent or the like. Therefore, unlike so-called permanent resists used in printed circuit boards and the like, no resist film derived from the present photosensitive composition remains in the final product, such as a microchip.

[0157] An example of the present invention will be described below. However, the present invention is not limited to this example. In the example, "parts" and "%" are by mass unless otherwise specified.

[0158] The following compounds 1 to 7 were prepared. The composition and ligand structure of each compound are １ Measurement was performed by H-NMR (400 MHz). The peak splitting is represented by the following abbreviations: brs stands for broad singlet, brd for broad doublet, brt for broad triplet, brm for broad multiplet, m for multiplet, s for singlet, d for doublet, t for triplet, and q for quartet. The measurement sample and the internal standard were weighed and mixed, and the following abbreviations were used: １H-NMR measurement allows the weight proportion of a specific ligand component to be quantified. Molecular weight measurement by LC-mass was performed using the following method. LC-Mass equipment: Waters Xevo G2-XS Qtof. Ionization method: ESI (electrospray ionization, capturing both positive and negative ions). LC eluent: A mixture of acetonitrile and THF. In TG-DTA measurement, the weight of the ligand contained in the sample was calculated from the weight loss that occurred during the process of heating the sample to 600°C.

[0159] <Synthesis of Compound 1> 2.36 g (4.89 mmol) of tris(p-tolyl)bismuth complex compound, 5.23 g (14.9 mmol; manufactured by Tokyo Chemical Industry Co., Ltd.), and 100 mL of dehydrated toluene were placed in a reaction vessel under a nitrogen atmosphere and heated under reflux for 6 hours. After returning the mixture to room temperature, the mixture was concentrated under reduced pressure, and the residue was subjected to NMR analysis, which confirmed that the compound had the structure shown in formula (3) below (5.80 g, yield 94%).

[0160] １ H-NMR(CDCl3); 7.73 (brd, 6H), 7.57-7.50 (brm, 6H), 7.40-7.32 (brm, 6H), 7.29-7.25 (brm, 6H), 4.94-3. 97 (brm, 15H), 3.13-2.96 (brm, 3H), 2.23 (brt, 3H), 1.65 (brs, 9H), 1.43-1.26 (brm, 6H).

[0161]

[0162] ​<Synthesis of Compound 2> In a nitrogen atmosphere, 1.0 g (1.9 mmol) of tris(p-hydroxymethylphenyl)bismuth and 16 mL of dehydrated dimethyl sulfoxide were dispersed in a reaction vessel, and 1.1 g (5.8 mmol) of 1-isocyanatonaphthalene was added dropwise to the dispersion in an ice bath. The mixture was stirred at 90°C for 9 hours, and then 5 mL of MeOH and 10 mL of water were added in an ice bath, resulting in the precipitation of a solid. The precipitated solid was separated by filtration and washed with dichloromethane and ethanol. The resulting solid was dissolved in 50 mL of THF and added dropwise to 200 mL of MeOH, resulting in the precipitation of a solid, which was then separated by filtration. The solid was dried in a vacuum, and 1.3 g of the resulting solid was analyzed by NMR, confirming that it had the structure shown in formula (4) below.

[0163] １ H-NMR (DMSO-d6); 9.66 (s, 3H), 8.05 (m, 3H), 7.91 (m, 3H), 7.79 (d, 6H), 7.73 (d, 3H), 7.62 (d, 3H), 7.49 (m, 15H), 5.16 (s, 6H)

[0164]

[0165] <Synthesis of Compound 3> Under a nitrogen atmosphere, 2.24 g (4.64 mmol) of tris(p-tolyl)bismuth complex compound, 5.16 g (14.4 mmol) of 2-(9H-fluoren-9-ylmethoxycarbonylamino)benzoic acid, and 100 mL of dehydrated toluene were placed in a reaction vessel and heated to reflux for 6 hours. After returning the mixture to room temperature, the precipitated solid was filtered and dried under vacuum, yielding 1.26 g of solid. NMR analysis of the solid confirmed that it had the structure shown in formula (5) below, with n = 3. 0.47 g of the resulting solid was dissolved in 5 mL of DMSO, and 2 mL of deionized water was added to perform hydrolysis. A solid precipitated. The solid was filtered, dried under vacuum, and analyzed by NMR, confirming that it had the structure shown in formula (5) below. Quantifying the weight ratio of the ligand using NMR revealed that n = 3 or less, suggesting that the oxocluster structure was formed by hydrolysis.

[0166] The number of protons per ligand is given.​１ H-NMR (DMSO-D6); 11.4 (br, 1H), 8.2-6.9 (m, 12H), 4.5-4.3 (m, 3H)

[0167]

[0168] <Synthesis of Compound 4> Under a nitrogen atmosphere, 1.00 g (1.90 mmol) of tris(p-hydroxymethylphenyl)bismuth and 20 mL of dehydrated dimethyl sulfoxide were placed in a reaction vessel and dissolved at room temperature. 1,3-bis(isocyanatomethyl)benzene (0.29 g, 1.53 mmol) was added dropwise and stirred at 90°C for 1 hour. 1-Isocyanatoadamantane (0.97 g, 5.47 mmol) was added dropwise to the solution, followed by further stirring at 90°C for 1 hour. While cooling the solution with ice, 10 mL of water was slowly added dropwise, resulting in the precipitation of a solid. The precipitated solid was filtered off, yielding 2.8 g of a solid. The resulting solid was dissolved in dichloromethane and filtered to remove insoluble matter. The resulting solution was purified by silica gel column chromatography using methylene chloride and ethyl acetate. The purified solution was concentrated, yielding 0.38 g of the target product as a solid. NMR and GPC analyses confirmed that the product had a molecular weight of 2,854 and a structure represented by formula (6).

[0169] １ H-NMR (DMSO-D6); 7.8-6.8 (m, 36H), 5.1-4.8 (m, 18H), 4.3-4.1 (m, 8H), 2.0-1.4 (m, 75H)

[0170]

[0171] ​<Synthesis of Compound 5> Under a nitrogen atmosphere, 1.75 g of zirconium propoxide (70% 1-propanol solution) (2.51 g, 5.3 mmol as a 70% solution), 7.51 g (21.4 mmol) of (S)—N-(9-fluorenylmethoxycarbonyl)piperidine-2-carboxylic acid, and 50 mL of dehydrated THF were placed in a reaction vessel and heated under reflux for 6 hours. After returning to room temperature, the mixture was concentrated under reduced pressure. The residue was dissolved in dichloromethane and added dropwise to aqueous acetonitrile. The precipitated solid was collected by filtration and dried in vacuo. NMR analysis of the resulting solid confirmed that it was represented by the following formula (7). LC-mass analysis detected a molecular weight of 4074 as the main peak, confirming that it was a cluster compound.

[0172] The number of protons per ligand is given. １ H-NMR (CDCl3); 8.0-6.8 (m, 8H), 5.2-2.8 (brm, 6H), 2.4-1.9 (brm, 1H), 1.9-0.8 (brm, 5H)

[0173]

[0174] <Synthesis of Compound 6> Under a nitrogen atmosphere, 2.00 g (9.58 mmol) of monobutyltin oxide, 3.70 g (10.5 mmol) of (S)—N-(9-fluorenylmethoxycarbonyl)piperidine-2-carboxylic acid, and 100 mL of dehydrated toluene were placed in a reaction vessel and heated to reflux for 1 hour. After returning the mixture to room temperature, the mixture was concentrated under reduced pressure to obtain a residue. The residue was dissolved in dichloromethane and added dropwise to aqueous acetonitrile. The precipitated solid was recovered by filtration and dried in vacuo. NMR analysis of the obtained solid confirmed that it was represented by the following formula (8). LC-mass analysis detected a molecular weight of 4282 as the main peak, confirming that it was a cluster compound.

[0175] The number of protons per ligand is given. １H-NMR (CDCl3); 7.8-7.2 (m, 8H), 5.1-3.9 (brm, 5H), 3.3-2.9 (brm, 1H), 2.4-2.1 (brm, 1H), 1.8-1.1 (brm, 13H), 1.0-0.6 (brm, 4H)

[0176]

[0177] <Synthesis of Compound 7> Under a nitrogen atmosphere, 0.90 g (1.9 mmol, Tokyo Chemical Industry Co., Ltd., 70% 1-propanol solution) of tetrabutoxyhafnium, 5.04 g (14.3 mmol) of (S)—N-(9-fluorenylmethoxycarbonyl)piperidine-2-carboxylic acid, and 100 mL of dehydrated toluene were placed in a reaction vessel and heated at 60°C for 6 hours. After returning to room temperature, the mixture was concentrated under reduced pressure to obtain a residue. The residue was dissolved in dichloromethane and added dropwise to aqueous acetonitrile. The precipitated solid was collected by filtration and dried in vacuo. NMR analysis of the obtained solid confirmed that it was the compound represented by the following formula (9). LC-mass analysis detected a molecular weight of 3052 as the main peak, confirming that it was a cluster compound.

[0178] The number of protons per ligand is given. １ H-NMR (CDCl3); 7.8-7.0 (m, 8H), 5.1-3.6 (brm, 5H), 3.4-2.8 (brm, 1H), 2.4-2.0 (brm, 1H), 1.8-1.0 (brm, 8H)

[0179]

[0180] <Preparation of Photosensitive Composition (Resist Solution)> [Example 1] The above residue of Compound 1 was dissolved in dichloromethane and added dropwise to aqueous methanol, causing hydrolysis and reprecipitation, resulting in a powder. The resulting powder was a compound with the structure shown in formula (10) below, and based on the weight loss measured by TG-DTA and the weight ratio of the ligand quantified by NMR, n = 1.5. In other words, it is presumed to be an oxocluster compound produced by hydrolysis. The NMR peak information and the number of protons per ligand are listed below.

[0181] １ H-NMR (CDCl3); 8.0-7.0 (brm, 8H), 5.1-3.6 (brm, 5H), 3.4-2.8 (brm, 1H), 2.4-2.0 (brm, 1H), 1.8-1.0 (brm, 6H)

[0182] This powder was dissolved in ethyl lactate at a concentration of 5% by mass, and the solution was filtered through a 0.2 μm filter to obtain the resist solution of Example 1.

[0183]

[0184] The prepared resist solution was applied to a pattern formation substrate (silicon wafer) by spin coating to form a resist film with a thickness of approximately 50 nm. The resulting resist film was baked at 90°C for 90 seconds, and then patterned using an electron beam lithography system (electron beam acceleration voltage: 100 keV).

[0185] <Development> After pattern writing, the pattern was developed with 4-methyl-2-pentanol (25°C, 60 seconds) to obtain a positive pattern. The resolution obtained by electron beam writing is summarized in Table 1 below.

[0186] Comparative Example 1 Preparation of Photosensitive Composition (Resist Solution) PMMA (poly(methyl methacrylate), manufactured by Aldrich) was dissolved in propylene glycol monomethyl ether acetate to a concentration of 5% by mass, and the solution was filtered through a 0.2 μm filter to obtain a resist solution of Comparative Example 1. Using the resist solution of Comparative Example 1, a resist film was formed and a pattern was drawn in the same manner as in Example 1.

[0187] <Development> After pattern writing, the pattern was developed with propylene glycol monomethyl ether acetate (25°C, 60 seconds) to obtain a positive pattern. The resolution obtained by electron beam writing is summarized in Table 1 below.

[0188] <Evaluation> When the pattern was resolved after development, it was evaluated as "good", and when the pattern was not resolved, it was evaluated as "poor".

[0189]

[0190] ​<Sensitivity Measurement> [Example 1] The resist solution prepared in Example 1 was applied by spin coating to a pattern-forming substrate (silicon wafer) to form a resist film with a thickness of approximately 50 nm. The resulting resist film was baked at 90°C for 90 seconds, then exposed to extreme ultraviolet (EUV) radiation at various doses. The film thickness obtained after development was measured using a contact profilometer, and the dose of extreme ultraviolet radiation at which the amount of change in film thickness reduction was maximized was determined as the sensitivity. The exposure doses are summarized in Table 2 below.

[0191] Comparative Example 1 The exposure dose of extreme ultraviolet light was determined as sensitivity in the same manner as above using the resist solution prepared in Comparative Example 1. The exposure doses are summarized in Table 2 below.

[0192]

[0193] [Results] From the above results, it was confirmed that Example 1, compared with Comparative Example 1, could achieve a high resolution of hp100 nmLS or hp50 nmLS as shown in Table 1, but Example 1 (photosensitive composition containing the compound of the present invention) had higher sensitivity than the photosensitive composition containing PMMA of the known technology as shown in Table 2.

[0194] <Preparation of Photosensitive Composition (Resist Solution)> Powders of compounds 2 to 7 were dissolved in cyclopentanone at a concentration of 5% by mass, and the solution was filtered through a 0.2 μm filter to obtain resist solutions of Examples 2 to 7.

[0195] <Analysis of resist film before and after exposure> The elemental composition of the resist film with a thickness of about 50 nm, which was prepared for the sensitivity measurement, was analyzed by XPS (X-ray photoelectron spectroscopy). In addition, to observe changes due to exposure and development, the resist film was analyzed after EUV exposure and development for the sensitivity measurement.

[0196] The XPS analysis conditions are shown below. XPS instrument: KRATOS ULTRA2. X-ray source and output: Monochromated Al-Kα, output 15 kV-75 W (5 mA) to obtain wide spectra, output 15 kV-225 W (15 mA) to obtain narrow spectra. Analysis: Peaks corresponding to O(1s), C(1s), N(1s), Bi(4f), and aromatic carbon (C π-π*) were detected from the XPS wide and narrow spectra, and the atomic ratios were quantified using the software provided with the XPS instrument. Specifically, the atomic ratios of O / Bi, C / Bi, and N / Bi, as well as the ratio (area %) of aromatic carbon (C π-π*) to the total C(1s) peaks were analyzed. The results are shown in Table 3 below.

[0197]

[0198] These results indicate that the ratios of O, C, and N to Bi all decreased, and that the partial structure represented by formula (1) above was decomposed and removed during the EUV exposure and development processes. Given the particularly large decrease in C / Bi and the decrease in the aromatic carbon content within the carbon, it is speculated that decomposition of the (9-fluorenyl)methylene group bonded to the carbamate in compound 1 occurred. In other words, it is speculated that the specific partial structure represented by formula (1) contained in the complex of the present invention contributes to its high performance as a resist for forming positive patterns.

Claims

1. A compound having a metal atom and a ligand, characterized in that the ligand contains a partial structure represented by the following formula (1): [In the above formula (1), R １ and R ２ are each independently a hydrogen atom or an arbitrary substituent, and may be the same or different, and may form a ring. １ , R ２ cannot be a hydrogen atom at the same time. ３ is the alpha hydrogen-containing substituent on the oxygen side of the carbamate.

2. The compound according to claim 1 is a compound having a P-block metal atom and a ligand, wherein the ligand contains a partial structure represented by the following formula (1): [In the above formula (1), R １ and R ２ are each independently a hydrogen atom or an arbitrary substituent, and may be the same or different, and may form a ring. １ , R ２ cannot be a hydrogen atom at the same time. ３ represents an optionally substituted 2-propenyl group or an optionally substituted arylmethylene group.

3. The compound according to claim 1, wherein the partial structure represented by formula (1) is the following formula (1-1) or (1-2): [In the above formula (1-1), Ar is an aryl group, and R １６ ~R １９ are each independently a hydrogen atom or an arbitrary substituent, and may be the same or different. [In the above formula (1-2), Ar is an aryl group, and R ３ is R in the above formula (1) ３ and R ２０ ~R ２２ are each independently a hydrogen atom or an arbitrary substituent, and may be the same or different. m is an integer of 0 or 1 or more.

4. The compound according to claim 3, wherein the aryl group is represented by the following formula (2-1) or (2-2): [In the above formula (2-1), R ４ ~R ８ are each independently a hydrogen atom or any substituent, and may be the same or different, with at least one of them being a bond to Ar in the partial structure represented by formula (1-1) or (1-2) above. The dashed line represents a bond to the metal atom.] [In the above formula (2-2), R ９ ~R １５ are each independently a hydrogen atom or any substituent, and may be the same or different, and at least one of the substituents is a bond to Ar in the partial structure represented by the above formula (1-1) or (1-2). k represents an integer of 0 or 1 or more. The dashed line represents a bond to the metal atom.] 5. In the partial structure represented by the formula (1), R １ and R ２ The compound of claim 1 , wherein 6. In the partial structure represented by the formula (1), R １ and R ２ The compound according to claim 5 , wherein:

7. The compound according to claim 5, wherein the ring has a structure represented by any one of the following formulas (2-3) to (2-5): [In the above formula (2-3), R ３ is R in the above formula (1) ３ The moiety corresponding to the hydrogen atom may be any substituent. The dashed line represents a bond to the metal atom.] [In the above formula (2-4), R ３ is R in the above formula (1) ３ The moiety corresponding to the hydrogen atom may be any substituent. The dashed line represents a bond to the metal atom.] [In the above formula (2-5), R ３ is R in the above formula (1) ３ The moiety corresponding to the hydrogen atom may be any substituent. The dashed line represents a bond to the metal atom.] 8. In the partial structure represented by the formula (1), R ３ The compound according to claim 1, wherein the substituent represented by the formula: is an optionally substituted benzyl group or an optionally substituted (9-fluorenyl)methyl group.

9. The partial structure represented by the formula (1) is the formula (1-2), and R in the formula (1-2) ３ is a (9-fluorenyl)methyl group, and R ２２ is a hydrogen atom, m is 0, and R ９ is a bond of Ar in the partial structure represented by formula (1-2), and k is 0.

10. The compound of claim 1, wherein the molecular weight of the compound is 2500 or greater.

11. The compound according to claim 1, wherein the molecular weight of the compound per partial structure represented by the formula (1) is 110 to 500.

12. The compound of claim 2, wherein the P-block metal atom is bismuth.

13. The compound of claim 1, wherein the compound is a complex compound.

14. The compound according to claim 13, wherein one to three of said ligands are coordinated to one of said metal atoms.

15. A photosensitive composition comprising the compound according to any one of claims 1 to 14 and an organic solvent.

16. A photosensitive composition comprising the compound according to any one of claims 1 to 14 in a concentration of 30 to 100% by weight of total solids.

17. The photosensitive composition according to claim 15, wherein the photosensitive composition is used to form a photosensitive layer having a thickness of 50 nm on a substrate, and when predetermined regions of the photosensitive layer are irradiated with EUV to perform pattern exposure, and the exposed photosensitive layer is developed with 4-methyl-2-pentanol, the exposed portions of the photosensitive layer are selectively removed.

18. A pattern formation method comprising the steps of forming a photosensitive layer on a substrate using the photosensitive composition according to claim 15, irradiating predetermined areas of the photosensitive layer with actinic radiation to perform pattern exposure, and developing the exposed photosensitive layer to selectively remove exposed or unexposed areas of the photosensitive layer.

19. The pattern forming method according to claim 18, wherein the actinic radiation has a wavelength of 6 to 15 nm.

20. The pattern formation method according to claim 18, wherein the development treatment is carried out using a developer, and the developer is an organic solvent having a solubility parameter (SP value) of 7.5 to 11.

21. A substrate having a patterned layer obtained by the patterning method according to claim 18.

22. A method for manufacturing a substrate, in which a pattern layer is formed by the pattern forming method according to claim 18.

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