Tin compounds, tin compositions, methods of making the same, resist solutions, pattern forming methods, thin films, patterned thin films, and methods of making substrates

Abstract

Provided is a tin compound that is a high-performance resist material by having solubility, hydrophobicity, resist sensitivity, and the like in balance. A tin compound that is a tin compound having a tin atom, an organic group R, and an oxygen ligand and / or a hydroxyl ligand, wherein two or more of the organic group R having 1 to 30 carbon atoms are contained in one molecule of the tin compound, and a Sn-O-Sn structure is contained.

Description

Technical Field

[0001] This invention relates to tin compounds, tin compositions, methods for manufacturing the same, resist solutions, patterning methods, thin films, patterned thin films, and methods for manufacturing substrates. Background Technology

[0002] In recent years, against the backdrop of the shift towards a highly information-based society, there is a demand for processing larger volumes of information at higher speeds and with higher precision, leading to increasingly sophisticated technologies related to semiconductor devices, such as integrated circuits.

[0003] The evolution of semiconductor design has necessitated the formation of unprecedentedly finer features on semiconductor substrate materials, with each feature being approximately 22 nanometers (nm) or smaller, and in some cases, less than 10 nm. One challenge in fabricating devices with such fine features is the ability to reliably and reproducibly form photolithographic masks with sufficient resolution. Achieving feature sizes smaller than the wavelength of light requires complex high-resolution techniques such as multiple patterning. Therefore, the development of photolithography techniques using shorter wavelengths of light, such as extreme ultraviolet (EUV) light with wavelengths of 10 nm to 15 nm (e.g., 13.5 nm), is of great importance.

[0004] Existing organic chemical amplification resists (CARs), particularly in the EUV region, exhibit low adsorption coefficients and are prone to diffusion blurring due to photoactivated chemical species, high linewidth roughness (LWR), and pattern collapse, posing potential drawbacks for use in EUV lithography. Therefore, there is a need for improved EUV photoresist materials with properties such as higher sensitivity, lower linewidth roughness (LWR), and superior etch resistance.

[0005] Therefore, in recent years, metallic materials using organotin compounds and the like have begun to be used as resists particularly suitable for EUV. Specifically, for example, alkyltin oxo-hydroxy compounds synthesized by hydrolysis of high-purity monoalkyltin compounds have been reported as resist materials for EUV applications, and it has been reported that very fine negative patterning can be achieved with high resolution and low linewidth roughness (LWR). In addition, excellent sensitivity has been reported as an alkyl group, especially a branched alkyl group (Patent Document 1).

[0006] In addition, it has been reported that monoalkyltin compounds, which contain few dialkyltin compounds as impurities, exhibit excellent gas release reduction when used as resist materials (Patent Document 2).

[0007] Furthermore, alkyltin oxo-hydroxy compounds synthesized from hydrolyzable tin compounds having two or more alkyl groups have been reported to achieve a balance between high sensitivity and low linewidth roughness (LWR) (Patent Document 3). Additionally, examples of synthesizing alkyltin oxo-hydroxy compounds by mixing organometallic compounds having hydrolyzable groups without alkyl groups have been reported (Patent Document 4).

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2021-21953

[0011] Patent Document 2: Japanese Patent Publication No. 2021-519340

[0012] Patent Document 3: Japanese Patent Publication No. 2019-500490

[0013] Patent Document 4: Japanese Patent Application Publication No. 2023-27078 Summary of the Invention

[0014] The problem that the invention aims to solve

[0015] However, the alkyltin oxy-hydroxy compounds reported to date are insufficient to meet the performance requirements as photoresist materials. In particular, as photoresist materials, the optimization of the alkyl structure selection and complexation composition, which affect the sensitivity and hydrophobicity related to performance and quality, has not been implemented. The preferred cluster structure and alkyl composition in alkyltin oxy-hydroxy compounds are still unclear.

[0016] Therefore, in this invention, under such circumstances, tin compounds and / or tin compositions are provided that can be used as high-performance resist materials by having a balanced combination of properties such as solubility, hydrophobicity, and resist sensitivity.

[0017] Methods for solving problems

[0018] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that the above-mentioned objective can be achieved by using a tin compound having tin atoms, organic groups R, and oxygen ligands and / or hydroxyl ligands, and containing a Sn-O-Sn structure, and including two or more organic groups R in one molecule.

[0019] That is, the present invention has the following aspects. [1]

[0021] A tin compound having tin atoms, an organic group R, and oxygen ligands and / or hydroxyl ligands, wherein, The above-mentioned tin compound contains two or more of the above-mentioned organic groups R in one molecule, and contains a Sn-O-Sn structure. The organic group R mentioned above has 1 to 30 carbon atoms. [2]

[0023] According to the tin compound described in [1], wherein the tin compound is composed of the formula RSnO (3 / 2-X / 2) (OH) X (where 0≤x≤3) represents the expression. [3]

[0025] According to the tin compound described in [1] or [2], wherein the tin compound contains a component of the chemical formula (RSn). 12 O 14 (OH)6 +2 Compounds that represent cations. [4]

[0027] The tin compound according to any one of [1] to [3], wherein the number of carbon atoms of the organic group R is 3 to 10. [5]

[0029] The tin compound according to any one of [1] to [4], wherein the organic group R is a hydrocarbon group. [6]

[0031] The tin compound according to any one of [1] to [5], wherein the above-mentioned organic group R is a hydrocarbon group, and 20 mol% to 99 mol% of the substituents constituting the above-mentioned organic group R are secondary hydrocarbon groups R. 2 . [7]

[0033] The tin compound according to any one of [1] to [5], wherein the above-mentioned organic group R is a hydrocarbon group, and 1 mol% to 50 mol% of the substituents constituting the above-mentioned organic group R are tertiary hydrocarbon groups R. 3 . [8]

[0035] The tin compound according to any one of [1] to [5], wherein the above-mentioned organic group R is a hydrocarbon group, and 1 mol% to 50 mol% of the substituents constituting the above-mentioned organic group R are cyclic hydrocarbon groups R. c . [9]

[0037] The tin compound according to any one of [1] to [5], wherein the above-mentioned organic group R is a hydrocarbon group, and 1 mol% to 50 mol% of the substituents constituting the above-mentioned organic group R are hydrocarbon groups having unsaturated bonds. u .

[10]

[0039] The tin compound according to any one of [1] to [9], wherein the organic group R includes isopropyl and tert-butyl.

[11]

[0041] The tin compound according to any one of [1] to

[10] , wherein the organic group R includes isopropyl and methylcyclopentyl.

[12]

[0043] The tin compound according to any one of [1] to

[11] , wherein the organic group R includes a saturated hydrocarbon group.

[13]

[0045] The tin compound according to any one of [1] to

[12] , wherein the organic group R includes 50 mol% or more of isopropyl.

[14]

[0047] A tin composition, which is a tin composition containing the tin compound according to any one of [1], [3] to

[13] , wherein when measured by ESI-mass, it contains three or more tin compounds (P3AB) containing cations represented by the chemical formula (R A Sn) x (R B Sn) y O 14 (OH)6 +2 .

[0048] Wherein, x is an integer of 0 < x < 12, y is an integer of 0 < y < 12, and x + y = 12. In the proportion of the composition of the organic group R calculated by NMR measurement of the above tin composition, the organic group with the largest proportion is taken as R A , and the organic group with the second largest proportion is taken as R B . The organic group R may include organic groups other than the above organic groups R A and R B .

[15]

[0050] The tin composition according to

[14] , wherein the total value of the content (%) of the above tin compound (P3AB) calculated by the following calculation formula A is 80% or more.

[0051] <Calculation formula A>

[0052] The content (%) of the above tin compound (P3AB) = [peak intensity of the above tin compound (P3AB)] / [total of peak intensities of the above tin compounds (P3AB), (P3A), and (P3B)]

[0053] The peak intensities mentioned above represent those measured using ESI-MASS.

[0054] The aforementioned tin compound (P3A) indicates that it contains only a single organic group R. A Tin compounds, wherein the aforementioned tin compound (P3B) represents a compound containing only a single organic group R. B Tin compounds.

[16]

[0056] According to the tin composition described in

[15] , the content (%) of the tin compound (P3AB-1) with the highest content (%) calculated by the above formula A exceeds that containing only a single organic group R. A The content of tin compound (P3A).

[17]

[0058] According to any one of

[14] to

[16] , the tin composition wherein the content (%) of each of the above-mentioned tin compounds (P3AB), (P3A), and (P3B) in the above-mentioned tin composition is set as the y-axis, and the content of the above-mentioned organic group R in one molecule is set as the y-axis. A The distribution shape of the curve plotted with the number of tin compounds as the x-axis shows that, when the tin compound with the highest content is set as tin compound (P3AB-1), the tin compound (P3AB-1) exhibits a peak (maximum point) and a single-peak distribution structure.

[18]

[0060] The tin composition according to any one of

[14] to

[17] , wherein the value of the molecular weight distribution Mw / Mn calculated from the peak molecular weight (Mi) and content (%) (Ni) of each of the tin compounds (P3AB), (P3A), (P3B) in the tin composition is 1.00001 to 1.05.

[19]

[0062] The tin composition according to any one of

[14] to

[18] , wherein, 119 The sum of the peak integrals (k1) of 5-coordinate Sn (-250ppm to -350ppm) and the sum of the peak integrals (k2) of 6-coordinate Sn (-450ppm to -600ppm) in Sn-NMR, relative to the sum of the peak integrals (k1+k2) of 6-coordinate Sn (-450ppm to -600ppm), is given by... 119 The ratio of the sum of all peak integral values ​​(including k1 and k2) in the range of 1000ppm to -1000ppm detected by Sn-NMR to (k3) [(k1+k2) / (k3)] is greater than 0.9.

[20]

[0064] The tin composition according to any one of

[14] to

[19] , wherein, 119The ratio (k1 / k2) of the total integrated peak value (k1) of 5-coordinate Sn (-250ppm to -350ppm) to the total integrated peak value (k2) of 6-coordinate Sn (-450ppm to -600ppm) in Sn-NMR is 0.5 to 2.5. [twenty one]

[0066] A method for manufacturing a tin compound and / or tin composition, comprising the following steps: manufacturing a tin compound having tin atoms, an organic group R, and oxygen ligands and / or hydroxyl ligands.

[0067] <Step 1> Two or more precursors RSnX3(A1) with different structures of the above organic group R are combined to obtain a precursor mixture.

[0068] <Step 2> Contact the above precursor mixture with the organic solvent complex in liquid water. [twenty two]

[0070] The method for manufacturing tin compounds and / or tin compositions according to

[21] includes a step of combining 100 parts by mass of the above-described precursor mixture with 100 parts by mass or more of an organic solvent. [twenty three]

[0072] A tin compound or tin composition manufactured by the manufacturing method described in

[21] or

[22] . [twenty four]

[0074] An anti-corrosion solution comprising any one of the tin compounds described in [1] to

[13] and / or any one of the tin compositions described in

[14] to

[20] , and an organic solvent.

[25]

[0076] A pattern forming method includes: a step of coating a resist solution described in

[24] onto a substrate; a step of exposing the substrate to radiation; and a step of developing the substrate using a developer.

[26]

[0078] A thin film on a substrate comprising any one of the tin compounds described in [1] to

[13] and / or any one of the tin compositions described in

[14] to

[20] .

[27]

[0080] A patterned thin film on a substrate, comprising any one of the tin compounds described in [1] to

[13] and / or any one of the tin compositions described in

[14] to

[20] .

[28]

[0082] A method for manufacturing a substrate, comprising the pattern forming method described in

[25] .

[0083] Invention Effects

[0084] The tin compounds and / or tin compositions of the present invention, by possessing balanced properties such as solubility, hydrophobicity, and resist sensitivity, can be used as high-performance resist materials. Attached Figure Description

[0085] Figure 1 This is the electrospray ionization mass spectrometry (ESI-MS) spectrum of tin hydrolysate H1.

[0086] Figure 2 This is the ESI-MS spectrum of tin hydrolysate H2.

[0087] Figure 3 This is the ESI-MS spectrum of tin hydrolysate H3.

[0088] Figure 4 This is the ESI-MS spectrum of tin hydrolysate H4.

[0089] Figure 5A It is tin hydrolysate H5 119 Sn-NMR spectrum.

[0090] Figure 5B It is tin hydrolysate H5 1 H-NMR spectrum.

[0091] Figure 5C It is tin hydrolysate H5 13 C-NMR spectrum.

[0092] Figure 5D This is the ESI-MS spectrum of tin hydrolysate H5.

[0093] Figure 5E It is the organic groups R of each tin compound in the tin composition of tin hydrolysate H5. A A curve is plotted with the number of items set as the x-axis and the content (%) set as the y-axis.

[0094] Figure 6A It is tin hydrolysate H6 119 Sn-NMR spectrum.

[0095] Figure 6B It is tin hydrolysate H6 1 H-NMR spectrum.

[0096] Figure 6C It is tin hydrolysate H6 13 C-NMR spectrum.

[0097] Figure 6D This is the ESI-MS spectrum of tin hydrolysate H6.

[0098] Figure 6E It is the organic groups R of each tin compound in the tin composition of tin hydrolysate H6. A A curve is plotted with the number of items set as the x-axis and the content (%) set as the y-axis.

[0099] Figure 7A It is tin hydrolysate H7 119 Sn-NMR spectrum.

[0100] Figure 7B It is tin hydrolysate H7 1 H-NMR spectrum.

[0101] Figure 7C This is the ESI-MS spectrum of tin hydrolysate H7. Detailed Implementation

[0102] The present invention will now be described based on examples of methods for carrying out the invention. However, the present invention is not limited to the embodiments described below.

[0103] It should be noted that when expressed as "α~β" (α and β are arbitrary numbers) in this invention, unless otherwise specified, it includes the meaning of "above α and below β", and also includes the meaning of "preferably more than α" or "preferably less than β".

[0104] In this invention, the expressions “above α” (α being any number) or “below β” (β being any number) also include the meaning of “preferably more than α” or “preferably less than β”.

[0105] In this invention, "γ and / or δ (γ and δ are arbitrary components or elements)" means only γ, only δ, or the combination of γ and δ.

[0106] Regarding the numerical ranges described in stages in this invention, the upper or lower limit of the numerical range for a certain stage can be arbitrarily combined with the upper or lower limit of the numerical ranges for other stages. Furthermore, the upper or lower limit of the numerical range described in this specification can also be replaced with the values ​​shown in the embodiments.

[0107] In this invention, "main component" refers to the component that has a significant impact on the properties of the object. The content of this component is usually 50% by mass or more in the object, preferably 55% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and may also be 100% by mass.

[0108] The following provides a detailed description of a tin compound and a tin composition according to one embodiment of the present invention. The definitions are shown in detail below: a tin compound refers to a compound represented by a single chemical formula. A tin composition refers to a mixture of tin compounds represented by two or more chemical formulas. Additionally, "tin compound" and / or "tin composition" synthesized by hydrolysis are sometimes referred to as "tin hydrolysate" for convenience.

[0109] <<Tin Compounds>>

[0110] The tin compound (P1) of one embodiment of the present invention is a tin compound having tin atoms, an organic group R, and an oxygen ligand and / or a hydroxyl ligand. It is a tin compound containing two or more of the aforementioned organic groups R in one molecule of the tin compound, and comprising a Sn-O-Sn structure, wherein the organic group R has 1 to 30 carbon atoms. Hereinafter, the substituent bonded to the tin atom is sometimes referred to as a "ligand".

[0111] Specifically, this tin compound (P1) is an organotin compound having two or more tin atoms and at least a Sn-O-Sn structure. Each tin atom typically has a ligand selected from organic groups R, oxygen ligands (Sn-O structure, Sn=O structure), and hydroxyl ligands (Sn-OH structure). In this embodiment, the organic groups R of the tin compound (P1) need to have two or more organic groups with different chemical structures. Sometimes, this tin compound (P1) has two or more tin atoms in one molecule, each of which has an R-Sn bond, and the organic groups R are two or more. Alternatively, sometimes one tin atom in one molecule has two or more organic groups R. It should be noted that the presence of two or more organic groups R in one molecule of this tin compound (P1) can be confirmed by ESI-mass analysis results, etc.

[0112] In this tin compound (P1), it is usually formed by the above-mentioned metal and ligand, but other metal atoms and ligands (substituents) may also be present without impairing its properties.

[0113] This tin compound (P1) is synthesized, for example, by hydrolysis using RSnX3 (a monoalkyltin compound, sometimes referred to as a "precursor") as the main raw material, for example, using the method disclosed in Japanese Patent Application Publication No. 2021-21953.

[0114] (The above X is a hydrolyzable group [a substituent that can form an oxygen ligand (Sn-O structure) or a hydroxyl ligand (Sn-OH structure) through a hydrolysis reaction].)

[0115] RSnX3, through hydrolysis, condensation, or other reactions with water or other suitable reagents under appropriate conditions, yields RSnOOH (where x=2), RSn(OH)3 (where x=3), and a condensate (where x=1) as hydrolysates of tin, represented by the following formulas. Furthermore, they also form reactive condensates with each other. Among these, compounds containing two or more organic groups R and exhibiting a Sn-O-Sn structure are tin compounds (P2). Tin compounds (P2) are compounds containing tin atoms and organic groups, and containing oxygen ligands and / or hydroxyl ligands. For example, compounds containing tin atoms with organic groups (optionally having hydroxyl ligands) forming a network structure via oxygen ligands.

[0116] [Formula]RSnO (1.5-(x / 2)) (OH) x (In the formula, 0≤x≤3)···(P2)

[0117] The reaction formula for obtaining the tin compound (P2) is shown below.

[0118] (Reaction formula)

[0119] ·RSnX3+3H2O→RSn(OH)3+3HX

[0120] ·RSn(OH)3→RSnO (1.5-(x / 2)) OH x +(x / 2)H2O

[0121] Among the compounds shown in this tin compound (P1), tin compounds with specific structures and numbers of tin atoms are sometimes used as high-performance photoresist materials. For example, compounds containing tin dodecomers represented by the chemical formula shown below (tin compounds) are stable, football-shaped tin dodecomer cluster compounds, which are useful as photoresist materials.

[0122] As a chemical formula, it is a cationic compound as shown below.

[0123] [Formula](RSn) 12 O 14 (OH)6 +2 ...(P3)

[0124] (In the above formula, +2 represents a divalent cation.)

[0125] In addition, tin compounds (P3) are usually divalent cationic compounds that are stabilized by counter anions (Z). The salts formed by combining with monovalent counter anions (Z) have the following chemical formula.

[0126] [Formula](RSn) 12 O 14 (OH)6(Z)2

[0127] There are no particular limitations on the counter anion (Z), and examples include OH anion, RCO2 anion, HCO2 anion, F anion, Cl anion, etc.

[0128] Examples of specific compounds that are tin compounds (P3) include, for example, the following synthetic examples described in the literature.

[0129] (nBuSn) 12 O 14 (OH)6 +2 The reported synthesis is described in Eychenne-Baron et al., "New synthesis of the nanobuilding block {(BuSn)}". 12 O 14 (OH)6} 2+ and exchange properties of {(BuSn) 12 O 14 (OH)6}(O3SC6H4CH3)2",J.Organometallic Chemistry 1998,567,137-142

[0130] (iPrSn) 12 O 14 (OH)6 +2 The reported synthesis is described in Puff et al., "Zur hydrolysevon monoorganylzinn-tri halogeniden(III.Isolierung und Roentgenstrukturanalyse von Verbindungen mit dem nueartigen Kaefig-ion[(i-PrSn)]. 12 O 14 (OH)6 +2 [J. Organometallic Chemistry 1989, 373, 173-184.] These compounds were identified by NMR, single-crystal X-ray structure, etc., and the analytical results are cited as supporting evidence in the embodiments of this invention.

[0131] <Tin composition (M) containing tin compounds (P1), (P2), and (P3)>

[0132] In the production of tin compounds (P1), (P2), or (P3) by hydrolysis, they are sometimes obtained as mixtures containing tin compounds having two or more structures. A mixture of two or more tin compounds (P1), (P2), or (P3) is called a tin composition (M). Specific components constituting the mixture include tin compounds (P1), (P2), or (P3) that contain two or more organic groups R in one molecule, and further contain two or more different organic groups R in one molecule. Additionally, mixtures of tin compounds (P1) or (P2) with different numbers of tin atoms per molecule, and tin compounds (P1), (P2), or (P3) with different compositions of substituents (organic groups R, oxygen ligands, hydroxyl ligands) bonded to tin atoms, are sometimes also obtained; these mixtures also correspond to tin compositions (M).

[0133] The following description specifically uses a tin composition (M) containing tin compound (P3) as an example, but the same applies to cases containing tin compounds (P1) and (P2). The structure, type, quantity, and content of the two or more tin compounds (P3) contained in this tin composition (M) can be analyzed, for example, by ESI-mass analysis. Specific analytical methods and examples are shown later. Regarding the types of tin compounds (P3) contained in the tin composition (M), the lower limit for the number detected by ESI-mass is preferably 3 or more, more preferably 5 or more, and even more preferably 7 or more. The upper limit is preferably 30 or less, preferably 25 or less, even more preferably 20 or less, even more preferably 15 or less, and even more preferably 10 or less. When the number of types of tin compounds (P3) contained in the tin composition (M) exceeds the above lower limits, it is sometimes possible to moderately reduce crystallinity, impart appropriate solubility when used as a resist solution, or prevent the formation of insoluble crystals during pattern formation, thereby reducing roughness. In addition, when the number of tin compounds (P3) with different structures and molecular weights is less than the above-mentioned upper limit, it is sometimes possible to form more uniform patterns or reduce the roughness during pattern formation.

[0134] [Organic group R]

[0135] In these tin compounds (P1, P2, P3, and so on), there is an organic group R attached to a Sn atom. The organic group R has 1 to 30 carbon atoms.

[0136] Considering the ease with which the R-group is removed during EUV exposure and the vaporization of the resulting components containing the R-group, the upper limit for the number of carbon atoms in the organic group R is 30 or less, preferably 20 or less, and more preferably 10 or less. Furthermore, from the viewpoint of the stability of the removed components, the lower limit for the number of carbon atoms in the organic group R is 1 or more, preferably 2 or more, and more preferably 3 or more.

[0137] Furthermore, examples of organic groups R include halogenated hydrocarbon groups; hydrocarbon groups containing heteroatoms such as oxygen and nitrogen atoms; and hydrocarbon groups. When used as a resist, the released gas generated during detachment after exposure is a hydrocarbon, and hydrocarbon groups are preferred from the perspective of minimizing the impact on semiconductor devices. In the case of containing heteroatoms, sometimes the resist properties, such as high decomposition resistance to EUV light, are improved, resulting in enhanced sensitivity.

[0138] When the organic group R is a hydrocarbon group, preferred examples of hydrocarbon groups are as follows. Examples include primary alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, and n-hexyl; secondary alkyl groups such as isopropyl, isobutyl, sec-butyl, and isopentyl; tert-butyl, tert-pentyl, cyclopentyl, cyclohexyl, methylcyclopentyl, and methylcyclohexyl; aryl groups such as phenyl, tolyl, benzyl, and naphthyl; aromatic hydrocarbon groups such as phenethyl, α-methylbenzyl, and 2-phenyl-2-propyl; alkenyl groups such as vinyl, 1-propenyl, allyl, and 3-butenyl; alkyl groups substituted with halogen atoms such as 2-fluoroethyl and 2-iodoethyl; and so on. From the perspective of the effects of the present invention, it is preferable to use two or more of these organic groups R together.

[0139] If we further list the structures, the following compounds can be listed. R in the diagram. a and R b The organic group R is an organic group having 1 to 10 carbon atoms. Examples of organic group R include haloalkyl groups; hydrocarbon groups containing heteroatoms such as oxygen atoms and nitrogen atoms; and hydrocarbon groups. When used as a photoresist, the gas released during removal after exposure is a hydrocarbon. From the perspective of minimizing the impact on the semiconductor device, a hydrocarbon group is preferred. The substituent A on the aromatic ring is a halogen atom or an organic group having 1 to 10 carbon atoms. Examples of such organic groups include hydrocarbon groups containing heteroatoms such as nitrogen atoms; and hydrocarbon groups are preferred.

[0140] [Chemical Formula 1]

[0141] [Chemical Formula 2]

[0142] (Preferred hydrocarbon group)

[0143] Of the hydrocarbon groups shown above, the primary hydrocarbon group R 1 secondary hydrocarbon group R2 tertiary hydrocarbon group R 3 Classified as cyclic hydrocarbon group R c Saturated and unsaturated hydrocarbon groups sometimes exhibit different properties when used as corrosion resist materials. From the viewpoint of sensitivity (photoreactivity), the case where the hydrocarbon group is saturated is preferred. Among the various categories, primary hydrocarbon groups R are listed as preferred substituents. 1 secondary hydrocarbon group R 2 tertiary hydrocarbon group R 3 From the viewpoint of sensitivity (photoreactivity) when used as an EUV resist, easily detachable secondary hydrocarbon groups (R) are preferred. 2 tertiary hydrocarbon group R 3 Further optimization of tertiary hydrocarbon group R 3 From a hydrophobic perspective, tertiary hydrocarbon R 3 The group that best enhances hydrophobicity near the tin atom is preferred from the viewpoint of solubility control. However, if the hydrophobicity is too high, a secondary hydrocarbon group (R) is sometimes preferred. 2 .

[0144] (A mixture of two or more organic groups R)

[0145] This tin compound contains an organic group R, which may have two or more types. For example, the organic group that constitutes the majority of the organic group R may sometimes have two different organic groups R. A and R B (It should be noted that, based on NMR-based compositional analysis of organic groups R, the organic group R with the highest proportion calculated by the following formula is designated as "R".) A The organic group that accounts for the second largest proportion is designated as "R". B It can also contain the organic group R. A and R B Other than organic groups. ). As an organic group R A and R B The structure is selected from the range of R mentioned above, as long as R A and R B There are no particular restrictions depending on the structure, but in the case of primary hydrocarbon R 1 secondary hydrocarbon group R 2 tertiary hydrocarbon group R 3 In selecting the range, to achieve the best balance between sensitivity stability and overall performance, R is the preferred choice. A and R B The structures each have different ranges. As a particularly preferred combination, "R" is preferred. A : Primary hydrocarbon group / R B : Tertiary hydrocarbon group R 3 “R” A : secondary hydrocarbon group / R B : Tertiary hydrocarbon group R3 ”, among which, in order to obtain a balance between sensitivity and hydrophobicity, “R A : secondary hydrocarbon group / R B : tertiary hydrocarbon group R 3 ” is particularly preferred. That is, from the aspect of the performance balance of the resist material, this “R A : secondary hydrocarbon group / R B : tertiary hydrocarbon group R 3 ” combination is particularly preferred.

[0146] (Calculation formula)

[0147] The composition ratio (mol%) of each organic group = [the ratio of each organic group R calculated from the integral value of H 1 -NMR / the total of the ratios of all organic groups calculated from the integral value of H 1 -NMR] × 100

[0148] It should be noted that the analysis method of each organic group R based on NMR is shown in the item of “Composition analysis of this stannic hydrolyzate” described later.

[0149] (Tin compound mixed with two or more organic groups R)

[0150] For example, regarding the tin compound (P3) containing a cation represented by (RSn) 12 O 14 (OH)6 +2 , when the organic group R is only composed of R A and R B , the tin compound (P3AB) containing R A and R B in one molecule is as follows.

[0151] The tin compound containing a cation represented by the chemical formula (R A Sn) x (R B Sn) y O 14 (OH)6 +2 ···(P3AB).

[0152] Among them, x is an integer of 0 < x < 12, y is an integer of 0 < y < 12, and x + y = 12.

[0153] If the compounds shown here are specifically written out, they will be tin compounds containing the following 11 kinds of cations. (R A Sn)1(R B Sn) 11 O 14 (OH)6 +2 、(RA Sn)2(R B Sn) 10 O 14 (OH)6 +2 、(R A Sn)3(R B Sn)9O 14 (OH)6 +2 、(R A Sn)4(R B Sn)8O 14 (OH)6 +2 、(R A Sn)5(R B Sn)7O 14 (OH)6 +2 、(R A Sn)6(R B Sn)6O 14 (OH)6 +2 、(R A Sn)7(R B Sn)5O 14 (OH)6 +2 、(R A Sn)8(R B Sn)4O 14 (OH)6 +2 、(R A Sn)9(R B Sn)3O 14 (OH)6 +2 、(R A Sn) 10 (R B Sn)2O 14 (OH)6 +2 、(R A Sn) 11 (R B Sn)1O 14 (OH)6 +2 .

[0154] It should be noted that, as tin compounds that do not contain more than two organic groups R in a single molecule, the following tin compounds (P3A) and (P3B) are shown below.

[0155] Contains (R) A Sn) 12 O 14 (OH)6 +2 The tin compound represented by the cation...(P3A)

[0156] Contains (R) B Sn) 12O 14 (OH)6 +2 The tin compound represented by the cation...(P3B)

[0157] Additionally, as a supplement, tin compounds (P3A) and (P3B) are tin compounds that do not contain two or more organic groups R, and therefore are not included in the tin compound (P3) of this embodiment.

[0158] (Detection methods for various tin compounds in tin compositions)

[0159] The structures and quantities of the tin compounds (P3AB), (P3A), and (P3B) shown above can be analyzed and detected by ESI-mass. Specific analytical examples are shown in the embodiments described later. Regarding the number of tin compounds (P3) contained in the tin composition (M), the lower limit for the quantity detectable by ESI-mass is preferably 3 or more, more preferably 5 or more, and even more preferably 7 or more. The upper limit is preferably 30 or less, more preferably 25 or less, even more preferably 20 or less, even more preferably 15 or less, and even more preferably 10 or less.

[0160] Furthermore, the number of different types of tin compounds (P3AB) contained in the tin composition (M) is more important in determining the properties of the resist. Regarding the preferred range of the number of such types, as measured by ESI-mass detection, the lower limit is preferably 2 or more, further preferably 5 or more, and even more preferably 8 or more. The upper limit is preferably 10 or less. When the number of different types of tin compounds (P3AB) contained in the tin composition (M) exceeds the above lower limit, crystallinity can sometimes be moderately reduced, providing appropriate solubility when used as a resist solution, or preventing the formation of insoluble crystals during pattern formation, thereby reducing roughness. Conversely, when the number is less than the above upper limit, there are fewer tin compounds (P3) with different structures and molecular weights, thus sometimes resulting in a more uniform pattern or reducing the roughness during pattern formation.

[0161] (The content of each tin compound in the tin composition (M))

[0162] The content of each tin compound in the tin compounds (P3AB), (P3A), and (P3B) shown above can be analyzed by quantitatively analyzing the peak intensity of the ESI-mass spectrum. Specific analytical examples are shown in the examples described later. As a quantitative method, the peak intensity shown in the ESI-mass spectrum of each tin compound (P3AB), tin compound (P3A), and tin compound (P3B) is used to quantify the content (%) of each tin compound.

[0163] Content (%) of each tin compound (P3AB) = [Peak intensity of each tin compound (P3AB)] / [Total peak intensity of each tin compound (P3AB), (P3A), and (P3B)]

[0164] It should be noted that in this calculation formula, the content of each tin compound (P3AB), (P3A), and (P3B) for which no peak is detected is 0 (%), but the content of other tin compounds for which a peak is detected can be calculated.

[0165] As the total value of the content (%) of each tin compound (P3AB) calculated by this calculation, it is preferably 50% or more, more preferably 60% or more, further preferably 70% or more, and further preferably 80% or more. As the upper limit, it is 100%. The higher this value, the smaller the proportion of the tin compound (P3A) and the tin compound (P3B) having a single organic group. Therefore, it is possible to reduce the dissolution residue in the resist solvent, improve the filtration property, and improve the storage stability for preventing crystallization, so it is preferred.

[0166] (Content of the tin compound (P3AB-1) having the largest content in the tin composition (M))

[0167] Let the tin compound (P3AB) having the largest content (%) in the tin composition (M) be (R A Sn) x’ (R B Sn) y’ O 14 (OH)6 +2 (P3AB-1).

[0168] Among them, x' is an integer where 0 < x' < 12, and y is an integer where 0 < y' < 12, and x' + y' = 12.

[0169] As the value of the content (%) of the tin compound (P3AB-1) calculated by the above formula, the upper limit is preferably 50% or less, more preferably 40% or less, further preferably 30% or less, and particularly preferably 20% or less. The lower limit is preferably 5% or more, more preferably 10% or more, and further preferably 15% or more. If the content of the tin compound (P3AB-1) is within the above preferred range, it becomes a tin composition containing an appropriate amount of the compound as the composition center. Therefore, it is possible to obtain a resist material with a high balance between crystallinity and uniformity and capable of forming excellent patterns. In addition, it is preferred that the content of the tin compound (P3AB-1) having the largest content exceeds that containing only a single organic group R AThe content of tin compound (P3A). In this case, the proportion of tin compound (P3A) with a single organic group is small, thus enabling a reduction in dissolved residue in the resist solvent, improved filterability, and improved storage stability to prevent crystallization.

[0170] (Molecular weight distribution of tin compound (P3AB) in tin composition (M))

[0171] Regarding the y-axis, the content (%) of each tin compound (P3AB), (P3A), and (P3B) in the tin composition (M) is set as the y-axis, and the organic group R in one molecule is set as the y-axis. A The distribution shape of the curve plotted with the number of molecules contained on the x-axis is preferably a single-peak distribution structure with the most abundant tin compound (P3AB-1) as the peak (maximum). When there are two or more peaks, the molecular weight distribution sometimes broadens, contributing to the roughness during pattern formation. Furthermore, when dissolved in resist solvents, the distribution of compounds with different solubilities does not necessarily broaden, sometimes leading to problems such as dissolution residue.

[0172] Furthermore, the number-average molecular weight Mn, weight-average molecular weight Mw, and molecular weight distribution Mw / Mn can be calculated from the peak molecular weight (Mi) and content (%) (Ni) of each tin compound (P3AB), (P3A), and (P3B). The specific calculation method, based on the formulas for calculating the molecular weight and molecular weight distribution of the polymer, is shown below.

[0173] • Number-average molecular weight: Mn = Σ(Mi × Ni) / Σ(Ni)

[0174] • Weight-average molecular weight: Mw = Σ(Mi 2 ×Ni) / Σ(Mi×Ni)

[0175] • Molecular weight distribution: Mw / Mn

[0176] The preferred molecular weight distribution value for the tin composition (M) calculated by this formula is preferably 1.00001 or higher at the lower limit, more preferably 1.00005 or higher, and even more preferably 1.0001 or higher. The upper limit is preferably 1.10 or lower, more preferably 1.05 or lower, even more preferably 1.01 or lower, particularly preferably 1.005 or lower, and especially preferably 1.002 or lower. If the molecular weight distribution is below the above upper limit, the structure and molecular size of each tin compound in the tin composition are consistent, which can sometimes reduce insoluble matter when dissolved in resist solvents, or reduce the roughness during pattern formation. In addition, if the molecular weight distribution is above the above lower limit, since it is a tin composition composed of a mixture of tin compounds with a certain number or more different molecular weights, it can sometimes moderately reduce crystallinity, increase solubility, or improve storage stability in resist solutions.

[0177] (Cyclic hydrocarbon group)

[0178] Regarding the organic group R, if it contains a cyclic hydrocarbon group R c The deformation of the ring-shaped skeleton increases its reactivity during exposure, which is sometimes preferable from the viewpoint of resist sensitivity. R is a preferred option. c Examples of cyclic skeletons contained therein include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. Furthermore, groups having an alkyl group such as a methyl group at the 1-position (the carbon bonded to Sn) are sometimes preferred, and are therefore preferred examples such as 1-methyl-cyclopropyl, 1-methyl-cyclobutyl, 1-methyl-cyclopentyl, 1-methyl-cyclohexyl, and 1-methyl-cycloheptyl. The cyclic hydrocarbon group R in the organic group R... c There is no particular limitation on the proportion, but the upper limit is preferably 50 mol% or less, more preferably 40 mol% or less, further preferably 35 mol% or less, and particularly preferably 30 mol% or less. The lower limit is preferably 1 mol% or more, more preferably 5 mol% or more, further preferably 10 mol% or more, and particularly preferably 15 mol% or more.

[0179] (Organic groups with unsaturated bonds)

[0180] Regarding the organic group R, if it contains a hydrocarbon group R with an unsaturated bond... u During exposure, the unsaturated bonds react or polymerize, causing structural changes, which is sometimes preferable from the perspective of resist sensitivity. A preferred option is a hydrocarbon group R with unsaturated bonds. uExamples of skeletons containing unsaturated bonds include alkenes, alkynes, dienes, trienes, benzenes, etc. From the viewpoint of reactivity and stability, alkenes are preferred, and from the viewpoint of reactivity, terminal alkenes are preferred. Specific preferred examples include vinyl, 1-propenyl, allyl, 3-butenyl, 4-pentenyl, etc. From the viewpoint of resist sensitivity, vinyl, 1-propenyl, and allyl alkenes close to the Sn atom are preferred. From the viewpoint of stability, unsaturated bonds separated from the Sn atom by two or more carbon atoms are preferred. From a balance perspective, allyl and 3-butenyl are preferred. The cyclic hydrocarbon group R in the organic group R... c There is no particular limitation on the proportion, but the upper limit is preferably 50 mol% or less, more preferably 40 mol% or less, further preferably 35 mol% or less, and particularly preferably 30 mol% or less. The lower limit is preferably 1 mol% or more, more preferably 5 mol% or more, further preferably 10 mol% or more, and particularly preferably 15 mol% or more.

[0181] (Preferred R) A With R B (Composition ratio)

[0182] As the preferred R A With R B The composition ratio, with the most abundant organic group R designated as "R". A The second most common organic group is designated as "R". B In the case of "R", A The content of [the substance] is preferably 50 mol% or more of the substituents constituting the organic group R, more preferably 60 mol% or more, and even more preferably 70 mol% or more. The upper limit is preferably 99 mol% or less, more preferably 95 mol% or less, and even more preferably 90 mol% or less. If the organic group R occupies a major proportion of the organic group R... A Within the aforementioned range, it is possible to achieve this without harming R. A By appropriately controlling crystallization during hydrolysis while maintaining the performance of the resist material, a tin compound with moderate crystallinity is provided. R is a preferred option. B The content of [specific ingredient] is preferably 50 mol% or less, more preferably 40 mol% or less, further preferably 35 mol% or less, and particularly preferably 30 mol% or less. The lower limit is preferably 1 mol% or more, more preferably 5 mol% or more, further preferably 10 mol% or more, and particularly preferably 15 mol% or more. In R B Within the aforementioned range, it is sometimes possible to achieve R without compromising its composition. A In the case of performance, give R B The properties of tin, or tin compounds with moderate crystallinity, can be obtained.

[0183] As RA Preferred secondary hydrocarbon group R 2 The preferred form is isopropyl.

[0184] Additionally, as R B Preferred tertiary hydrocarbon group R 3 cyclic hydrocarbon group R c Hydrocarbon group R with unsaturated bond u Any of the following, tertiary hydrocarbon group R 3 In this group, tert-butyl is preferred. Cyclic hydrocarbon group R c In this context, methylcyclopentyl is preferred. The hydrocarbon group R has an unsaturated bond. u In this context, butenyl is preferred.

[0185] In the above R A With R B In the combination, R A With R B The upper limit of the difference in the number of carbon atoms is preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. The lower limit is preferably 0 or more, more preferably 1 or more. If R A With R B If the difference in the number of carbon atoms is below the upper limit mentioned above, then the organic group R may be present. A With R B The difference in molecular weight and similar hydrophobicity can narrow the molecular weight distribution of tin compounds or homogenize their solubility in resist solvents, thereby reducing the roughness during pattern formation. On the other hand, if the difference in molecular weight is above the aforementioned lower limit, it is possible to moderately reduce crystallinity, increase solubility in resist solvents, or improve storage stability.

[0186] [Compositional Analysis of the Tin Hydrolysate]

[0187] This tin hydrolysate can be utilized using NMR ( 1 H-NMR, 13 C-NMR, 119 Analytical instruments such as Sn-NMR and related NMR and mass spectrometry are used to analyze the composition of contained organic groups. In NMR, it is possible to analyze the overall composition of the sample (the composition of the tin composition), such as the ligands with tin atoms (organic groups R, etc.), the coordination number of each tin atom, etc., and to identify the structure of organic groups R and quantify the average composition of the sample containing organic groups R (the composition of the tin composition).

[0188] Tin hydrolysate 119The ratio (k1 / k2) of the total integrated peak values ​​(k1) of 5-coordinate Sn (-250ppm to -350ppm) and the total integrated peak values ​​(k2) of 6-coordinate Sn (-450ppm to -600ppm) in Sn-NMR is preferably 0.5 to 2.5, more preferably 1.0 to 2.4, even more preferably 1.2 to 2.3, and particularly preferably 1.3 to 2.2. In this tin hydrolysate, 5-coordinate Sn has a high tendency to have OH groups, while 6-coordinate Sn has more coordination moieties, thus having a high tendency to bond OH groups only through Sn-O-Sn bonds without bonding OH groups. That is, it can be said that the higher the value of k1 / k2, the more OH groups there are, and the lower the value of k1 / k2, the fewer OH groups there are. The number of OH groups causes changes in the parameters of the tin compound's polarity related to the solubility in the resist solvent, and the parameters of the tin compound's hydrophobicity and hydrophilicity related to the resist performance. From the perspective of controlling its performance balance, it is preferable to control k1 / k2 within the above range.

[0189] Based on the molecular weight of the ions observed in mass analysis (sometimes also called mass spectrometry, "MS") (especially from the viewpoint of sensitivity and detection capability of unstable compounds based on soft ionization, ESI-mass analysis (electrospray ionization) is preferred), the molecular weight and molecular formula of each tin compound contained in the tin composition can be determined. That is, what is observed in NMR is the average composition of the entire sample (tin composition), while the composition of organic groups R observed in mass analysis represents the composition of organic groups R contained in a single molecule (the composition of each tin compound). In addition, by quantifying the intensity of each peak, the structure of the most abundant tin compound in the tin composition and the composition of its organic groups R can be identified, or the content of each tin compound can be quantified. It should be noted that since tin atoms, oxygen atoms, carbon atoms, hydrogen atoms, etc., present in tin compounds have isotopes, each tin compound provides a mass spectrum with more than two peaks. From the theoretical mass spectrum pattern of each tin compound, only the peak with the highest intensity is taken as the peak of each tin compound and analyzed for peak intensity quantification. Examples of these analyses are also illustrated in the items of the embodiments.

[0190] (Purity of the tin composition)

[0191] The method for calculating the purity of tin compositions based on NMR is shown below. Here, the "mol%" representing the purity in tin atom conversion refers to the ratio of tin atoms in the target compound to the total number of tin atoms in all compounds (including unidentified compounds) containing tin atoms. In practice... 119Sn-NMR uses the sum of the integrated values ​​of all observed peaks as the denominator and the integrated value of the peak of the compound being studied as the numerator for calculation. It should be noted that... 119 Sn-NMR measurements were performed in the range of 1000 to -1000 ppm, which is sufficient to determine the range of compounds analyzed in this study. For example, the purity of a tin composition consisting of 5-coordinated Sn and 6-coordinated Sn was determined by... 119 The sum of the integrated peak values ​​(k1) of 5-coordinate Sn (-250ppm to -350ppm) and the sum of the integrated peak values ​​(k2) of 6-coordinate Sn (-450ppm to -600ppm) in Sn-NMR is set as (k1+k2). 119 When the total integrated values ​​of all other peaks detected by Sn-NMR (in the range of 1000 to -1000 ppm, including k1 and k2) are set as (k3), the value is expressed as (k1+k2) / (k3). The larger this value, the lower the concentration of impurities other than 5-coordinate Sn and 6-coordinate Sn in the tin hydrolysate, which is therefore preferred. The lower limit is preferably 0.7 or more, more preferably 0.8 or more, further preferably 0.9 or more, particularly preferably 0.95 or more, and most preferably 0.99 or more. It should be noted that from the viewpoint of the determination sensitivity of this method, if peaks corresponding to k1 and k2 cannot be detected, it can be considered as 0.99 or more. The upper limit is 1.

[0192] According to this calculation method, compounds containing only tin atoms are included in the calculation. For example, if additives or solvents are added after the manufacture of this tin hydrolysate according to various uses, even if it contains this tin hydrolysate and tin compounds as other impurities, it is included in the scope of this tin hydrolysate as long as it contains this tin hydrolysate.

[0193] As 119 In Sn-NMR analysis, to improve sensitivity, the tin hydrolysate is dissolved at a high concentration and analyzed (using a solvent with a high concentration of solution), using multiple cumulative counts (more than 1000 times, preferably more than 10000 times), sufficient relaxation time (more than 1 second), reverse gate decoupling, and an appropriate measurement range (1000 to -1000 ppm). As a result, by using these methods, the detection limit for trace amounts of tin compounds (A2), (A3), and (A4) can be reached as low as 0.01 mol%. Furthermore, even if the sensitivity of the measured peak is insufficient, the detection sensitivity can be further improved by using a highly sensitive NMR (e.g., using a low-temperature probe in 600 MHz NMR), enabling detection up to 0.001 mol%.

[0194] It should be noted that, in addition to monoalkyl tin compounds (A1), the following tin compounds (A2), (A3), and (A4) may also be listed as possible tin compounds that may be contained in this tin hydrolysate.

[0195] ·R2SnX2 ····(A2)

[0196] SnX4 ····(A3)

[0197] ·RSn(NR')2(N(R')CHNR'2)···(A4)

[0198] [Crystallization of this tin hydrolysate]

[0199] When tin hydrolysate is used as a photoresist material to form a thin film, it is preferably a solid to ensure resistance to semiconductor processes (exposure, development, etching, etc.). In particular, controlling the properties of this solid, such as particle shape, form, crystallinity, and surface condition, within specific ranges is sometimes preferred as a photoresist material. Regarding crystallinity, it is important to control solubility (which contributes to development performance, coating performance, ease of filtration, and storage stability of the photoresist solution) and the surface condition of the solid (which contributes to hydrophobicity / hydrophilicity, substrate adhesion, etc.) while maintaining the properties derived from the chemical formula. Furthermore, crystallinity also affects adhesion to the substrate, roughness after exposure, ease of pattern collapse, and solubility during development; therefore, it needs to be appropriately controlled within the range required for its performance as a photoresist. Specifically, if the crystallinity is too high, it is difficult to dissolve in the photoresist solvent, causing problems in processes such as dissolution, filtration, and storage. Furthermore, excessively high crystallinity during coating and drying can sometimes lead to cracks or collapse of the patterns at the crystal interfaces or on the crystal surfaces. During exposure and development, high crystallinity results in larger crystal sizes, which can sometimes increase the roughness of the developed pattern. Conversely, insufficient crystallinity leads to poor adhesion to the substrate or low strength of the resist film. Consequently, the resist film may peel off during coating, drying, exposure, and development, or the pattern may collapse, or the roughness of the developed pattern may increase. As described above, in resist materials with excellent solubility, adhesion, and roughness, it is necessary to appropriately control the ratio of crystalline to amorphous components (amorphous matter) within a suitable range of crystallinity to achieve this specific range.

[0200] As an analytical method for crystallinity, XRD (X-ray diffraction) based analysis can be used, and it can be applied to any of the following: powders, molded bodies, thin films, and patterned thin films after exposure of the tin hydrolysate. Among the values ​​obtained from XRD, particularly the diffraction angle 2θ (°) of the maximum intensity peak and the half-width at half-maximum (FWHM) of the maximum intensity peak, as well as the number of detected peaks, can be used as numerical values ​​to indicate the crystallinity of the obtained tin compound. As shown in this embodiment, values ​​to two decimal places are valid for analytical precision; when comparing the diffraction angle 2θ (°) and FWHM (°), values ​​greater than 0.01 (°) are considered meaningful. Specific measurement methods are also shown in the embodiments.

[0201] The diffraction angle 2θ (°) of the peak with the highest intensity of the tin hydrolysate is preferably 5.00 to 15.00°, more preferably 3.00° or less, even more preferably 11.00° or less, particularly preferably 10.00° or less, and especially preferably 9.00° or less. The lower limit is more preferably 5.50° or more, even more preferably 5.80° or more, and especially preferably 6.00° or more. The diffraction angle 2θ (°) of the peak with the highest intensity is related to the lattice plane spacing of the crystal. If it is within the above-mentioned preferred range, the crystals of the tin compound are arranged with appropriate lattice plane spacing, which suppresses pattern collapse during pattern formation as crystals with moderate crystallinity and intensity, and can also reduce roughness during the formation of fine patterns.

[0202] The preferred range for the half-width at half-maximum (FWHM) of the maximum intensity peak is 1.00 to 4.00°, more preferably 3.50° or less, particularly preferably 3.00° or less, especially preferably 2.50° or less, and even more preferably 2.00° or less. The lower limit is more preferably 1.05° or more, even more preferably 1.10° or more, particularly preferably 1.20° or more, particularly preferably 1.43° or more, and even more preferably 1.50° or more. The FWHM of the maximum intensity peak is particularly strongly correlated with the crystallinity of the tin compound. When the FWHM is within the above-mentioned preferred range, parameters such as the solubility (which contributes to developing performance, coating performance, ease of filtration process, and storage stability of the resist solution) and the surface state of the solid (which contributes to hydrophobicity / hydrophilicity, substrate adhesion, etc.) required by the above-mentioned resist material can be controlled within an appropriate range.

[0203] The number of peaks detected at a diffraction angle of 2θ (°) within the range of 5.00 to 15.00° is preferably 5 or less, more preferably 3 or less, even more preferably 2 or less, and particularly preferably 1 or less. The lower limit is preferably 1 or more. It should be noted that 0 peaks indicates that no peaks were detected by the above analytical method. This tin hydrolysate tends to have lower crystallinity as the number of peaks decreases, but if there are 0 peaks, it indicates that no crystal structure was detected at all. That is, if the number of peaks is within the above preferred range, it has moderate crystallinity, and parameters such as the solubility required for the resist material (which helps with development performance, coating performance, ease of filtration process, and storage stability of the resist solution) and the surface state of the solid (which helps with hydrophobicity / hydrophilicity, substrate adhesion, etc.) can be controlled within an appropriate range.

[0204] [Solubility of this tin hydrolysate]

[0205] When this tin hydrolysate is used as a resist material, it is sometimes dissolved in the resist solvent described below, and used as a resist solution. The solubility of the tin hydrolysate refers to its solubility in the organic solvent used in preparing the resist solution. In the dissolved resist solution, it is preferable that it is completely dissolved without any insoluble matter or turbidity originating from the tin hydrolysate. Insoluble matter originating from the tin hydrolysate is a cause of performance degradation and malfunction when used as a resist material. Specific examples include performance degradation as a resist material due to defects in patterning (causing linewidth roughness (LWR), pattern collapse / reduced sensitivity), equipment contamination caused by impurities / foreign matter generated during etching, clogging / reduced productivity in filtration (filter) processes, etc.

[0206] (Resist solvent)

[0207] The tin hydrolysate dissolves in a resist solvent. Suitable resist solvents include organic solvents such as alcohols, esters, or combinations thereof. In particular, suitable solvents include, for example, aromatic compounds (e.g., xylene, toluene), ethers (anisole, tetrahydrofuran), halogen solvents (dichloromethane, chloroform), esters (propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate), alcohols (e.g., 4-methyl-2-pentanol, 4-methyl-2-propanol, 1-butanol, methanol, isopropanol, 1-propanol), and ketones (e.g., methyl ethyl ketone, cyclohexanone, 2-heptanone). These solvents can be used alone or in combination of two or more. For dissolving tin hydrolysates containing OH groups, an alcohol solvent is preferred, and 4-methyl-2-pentanol is more preferred. Furthermore, from the viewpoints of toxicity, regulatory restrictions, and volatility, 2-heptanone, 4-methyl-2-pentanol, and ethyl lactate are also preferred solvents in practical manufacturing processes.

[0208] The selection of these resist solvents is sometimes based on the solvent's own physical properties, such as solubility, volatility, flammability, toxicity, and viscosity. On the other hand, it is sometimes evaluated based on the stability (solution stability) of the resist solvent in the presence of dissolved tin hydrolysates or other materials. That is, after the components of the resist solution are dissolved and mixed, especially between solution preparation and film formation, the characteristics of the dissolved tin hydrolysates sometimes change as a result of the interactions (reactions, condensations, solvation, coordination, etc.) between the partial tin hydrolysates and the solvent. Solution stability based on these interactions is evaluated through the storage stability of the resist solution, as shown below. From the viewpoint of storage stability and stabilization based on OH group coordination, alcohol solvents are preferred.

[0209] (Methods for evaluating solubility)

[0210] The solubility of this tin hydrolysate is evaluated by comparing the turbidity (transparency) when the tin hydrolysate is dissolved in 4-methyl-2-pentanol at a certain concentration. Specifically, a mixture of tin hydrolysate equivalent to 2.0% by mass in 4-methyl-2-pentanol, as disclosed in Japanese Patent Application Publication No. 2019-500490, is prepared. The turbidity (transparency) of this liquid is compared with a standard turbidity solution, and the solubility of the corresponding tin hydrolysate is evaluated by visual inspection. As the standard turbidity solution, kaolin turbidity standard solutions (0 degrees (clear), 50 degrees, 100 degrees, 500 degrees, and 1000 degrees (white turbidity)) as shown in JIS K0110 are used. Turbidity values ​​close to those of the standard turbidity solution are evaluated as turbidity ratings from 1 to 5, as described below.

[0211] • Turbidity rating 1: 0 degrees (transparent)

[0212] Turbidity rating 2: 50 degrees

[0213] Turbidity rating 3: 100 degrees

[0214] Turbidity rating 4: 500 degrees

[0215] • Turbidity rating 5: 1000 degrees (cloudy)

[0216] [Storage stability of the resist solution]

[0217] The resist solution prepared by dissolving the tin hydrolysate should be stable without solid precipitation or sedimentation for at least one week, preferably two weeks or more, more preferably one month or more, further preferably three months or more, and particularly preferably six months or more, without stirring. As a specific method for evaluating storage stability, the solution sample can be stored at 20°C, and the turbidity can be evaluated using the same method after one week, two weeks, and one month following dissolution. Preferably, the turbidity in this evaluation does not change, indicating a stable resist solution that can be stored stably.

[0218] <<Raw Materials of Tin Hydrolysate>>

[0219] When manufacturing this tin hydrolysate as shown above, there are no particular limitations, but it is preferable to use the monoalkyltin compounds (A1) and (B1) shown below as raw materials (sometimes referred to as "precursors"). The monoalkyltin compounds (A1) and (B1) that can be used as precursors will be described below.

[0220] <Monoalkyltin compounds (A1)>

[0221] Monoalkyltin compounds (A1) are defined as compounds having one organic group and three hydrolytic groups X bonded to tetravalent tin. Specifically, they are represented by the following general formula (A1).

[0222] RSnX3 ····(A1)

[0223] (In the above general formula (A1), R is an organic group having 1 to 30 carbon atoms. X is selected from OR', NR'2, and C≡CR'. R' is an organic group having 1 to 10 carbon atoms. Examples of organic groups R' include haloalkyl groups; hydrocarbon groups containing heteroatoms such as oxygen and nitrogen atoms; and hydrocarbon groups. When used as a photoresist, the gas released during detachment after exposure is a hydrocarbon. Considering minimizing the impact on semiconductor devices, hydrocarbon groups are preferred. Furthermore, when there are two or more R's in the molecule, their structures can be different from each other or bonded together to form a cyclic structure.)

[0224] [Organic group R]

[0225] The organic group R has 1 to 30 carbon atoms. Other examples of the organic group R include haloalkyl groups; hydrocarbon groups containing heteroatoms such as oxygen and nitrogen atoms; and hydrocarbon groups. When used as a photoresist, the gas released during detachment after exposure is a hydrocarbon, and hydrocarbon groups are preferred from the perspective of minimizing the impact on semiconductor devices. In the case of containing heteroatoms, sometimes the photoresist properties such as high decomposition resistance to EUV light are improved, resulting in enhanced sensitivity.

[0226] Regarding the number of carbon atoms in the organic group R, considering the ease with which the R group detaches during EUV exposure and the vaporization of the resulting R group components, the upper limit for the number of carbon atoms in the organic group R is 30 or less, preferably 20 or less, and more preferably 10 or less. Furthermore, from the viewpoint of the stability of the detached components, the lower limit is 1 or more, preferably 2 or more, and more preferably 3 or more.

[0227] Regarding the organic group R, when used as a photoresist, the gas released during detachment after exposure is a hydrocarbon. Considering minimizing the impact on the semiconductor device, a hydrocarbon group is preferred. Specific examples of preferred hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclopentyl, and cyclohexyl; aryl groups such as phenyl, tolyl, benzyl, and naphthyl; aromatic hydrocarbon groups such as phenethyl, α-methylbenzyl, and 2-phenyl-2-propyl; alkenyl groups such as vinyl, 1-propenyl, allyl, and 3-butenyl; and alkyl groups substituted with halogen atoms such as 2-fluoroethyl and 2-iodoethyl. Two or more of these groups can be used together.

[0228] Further listing of structures would yield the following compounds. R in the diagram a and R b An organic group consisting of 1 to 10 carbon atoms. Examples of such organic groups include haloalkyl groups; hydrocarbon groups containing heteroatoms such as oxygen atoms and nitrogen atoms; and hydrocarbon groups. The substituent A on the aromatic ring is a halogen atom or an organic group with 1 to 10 carbon atoms. Examples of such organic groups include hydrocarbon groups containing heteroatoms such as oxygen atoms and nitrogen atoms; and hydrocarbon groups.

[0229] [Chemical Formula 3]

[0230] [Chemical Formula 4]

[0231] In addition, the hydrocarbon groups shown above are classified as primary hydrocarbon groups R. 1 secondary hydrocarbon group R 2 tertiary hydrocarbon group R 3 Typically, they are alkyl or aralkyl groups. As preferred examples of each classification, primary hydrocarbon R... 1 Examples include methyl, ethyl, n-propyl, n-butyl, isobutyl, benzyl, phenethyl, etc., and secondary hydrocarbon groups (R). 2 Examples include isopropyl, sec-butyl, cyclopentyl, cyclohexyl, cycloheptyl, α-methylbenzyl, etc., and tertiary hydrocarbon groups R. 3Examples include tert-butyl, tert-pentyl, 1-methyl-cyclopentyl, 1-methyl-cyclohexyl, and 2-phenyl-2-propyl. They sometimes exhibit different properties when used as resist materials. Hereinafter, if hydrocarbon groups are used as representative examples, from the viewpoint of sensitivity (photoreactivity) when used in their respective preferred EUV resists, easily detachable secondary hydrocarbon groups R are preferred. 2 tertiary hydrocarbon group R 3 From a hydrophobic perspective, tertiary hydrocarbon R 3 The presence of a tin atom maximizes hydrophobicity and is preferred from a solubility control perspective. However, in cases where hydrophobicity is excessively high, a secondary hydrocarbon group (R) may be preferred. 2 Furthermore, from the perspective of thermal stability affecting distillation, primary hydrocarbon groups tend to be less prone to disproportionation and can sometimes be easily purified. On the other hand, secondary and tertiary hydrocarbon groups are prone to disproportionation reactions, especially those with fewer carbon atoms (6 or less). These groups are unstable during distillation, and distillation, which usually achieves high purification efficiency, is often difficult due to thermal decomposition. Therefore, in the reaction stage before purification, such as distillation, it is more important to obtain high-purity tin compounds with low content of byproducts with similar boiling points.

[0232] [Substituent X]

[0233] The substituent X is not limited in structure as long as it is a hydrolyzable group capable of undergoing hydrolysis or similar reactions. Preferred examples, considering high reactivity, include OR', NR'2, and C≡CR'. From the viewpoint of hydrolysis reactivity, OR' and NR'2 are more preferred. R' is an organic group having 1 to 10 carbon atoms. Examples of such organic groups include haloalkyl groups; hydrocarbon groups containing heteroatoms such as oxygen or nitrogen atoms; and hydrocarbon groups. Furthermore, when there are two or more R's in the molecule, their structures can be different or bonded together to form a cyclic structure. Considering the balance between high hydrolysis reactivity and stability during synthesis, alkoxy groups are preferred for OR', and alkylamino groups are preferred for NR'2.

[0234] Specific examples of organic groups R' include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, tert-pentyl, 2-methyl-pentyl, trifluoroethyl, trifluoromethyl, etc. Examples of NR'2 include 1-pyrrolidinyl groups, where two substituents on the nitrogen atom are bonded together to form a 5-membered ring.

[0235] As a preferred substituent X, from the viewpoint of low boiling point and stability, the organic group R' is preferably an alkyl group without heteroatoms or a fluorinated alkyl group. Furthermore, from the viewpoint of low boiling point, a lower number of carbon atoms is preferred; from the viewpoint of thermal stability and stability to moisture, a higher number of carbon atoms is preferred. Specific examples of substituent X that offer an excellent balance of these properties include OR' (tert-butoxy, tert-pentoxy, 4-methyl-2-pentoxy, trifluoroethoxy, trifluoromethoxy), and NR'2 (dimethylamino, diethylamino, methylethylamino, pyrrolidinyl, etc.). From the viewpoint of hydrolytic reactivity when used as a corrosion resist material, OR' is preferred, with dimethylamino and diethylamino being most preferred; from the viewpoint of balancing stability and reactivity, NR'2 is preferred, with tert-butoxy, tert-pentoxy, and 4-methyl-2-pentoxy being most preferred.

[0236] Furthermore, the R in the molecule can bond with the organic groups contained in the substituent X to form a cyclic structure. Examples of compounds having the structure shown below can be cited as examples.

[0237] [Chemical Formula 5]

[0238] [Structure of monoalkyltin compound (A1)]

[0239] Monoalkyl tin compounds (A1) (hereinafter sometimes referred to as "tin compounds (A1)") are not particularly limited in structure and physical properties as long as they fall within the above range. When used as EUV resist materials, the following physical properties are sometimes preferred.

[0240] (Boiling point)

[0241] As for the boiling point when using tin compounds (Al), the boiling point at 1 torr is preferably below 300°C, more preferably below 250°C, even more preferably below 200°C, and particularly preferably below 150°C. The lower limit of the boiling point at 1 torr is generally above 0°C, preferably above 10°C, and more preferably above 20°C. If the boiling point is low, distillation can be carried out at low temperatures, which is preferred from the viewpoint of easy vapor deposition when used as a photoresist material. If the boiling point is above the above-mentioned lower limit, when used as an EUV photoresist, there is a tendency for the vapor deposition and reaction processes at high temperatures to become easier, or for the volatilization and dispersion of components and released gases to be suppressed due to the excellent thermal stability of the formed film.

[0242] (molecular weight)

[0243] The molecular weight of the tin compound (Al) is preferably 500 or less, more preferably 400 or less, and even more preferably 350 or less. The lower limit is preferably 150 or more, more preferably 180 or more, and even more preferably 200 or more. If the molecular weight is too high, the boiling point may become too high, making it difficult to perform vapor deposition when used as an EUV resist. If the molecular weight is too low, the boiling point may become too low, making processes involving high-temperature vapor deposition and reactions difficult, or resulting in insufficient thermal stability of the formed film, and causing problems with the volatilization and dispersion of components and released gases.

[0244] (Molecular weight difference between organic group R and substituent X)

[0245] There are no particular limitations on the molecular weight difference between the organic group R and the substituent X, but it is preferably 50 or less, more preferably 30 or less, even more preferably 20 or less, particularly preferably 10 or less, and especially preferably 6 or less. The lower limit is 0. By reducing the molecular weight difference between R and X, there is a tendency to reduce the mass difference of various gas releases when used as a photoresist, and to make it easier to set the conditions in the EUV process. In addition, in order to control the EUV sensitivity and boiling point of tin compounds, the molecular weight difference is sometimes adjusted by changing the substituents.

[0246] On the other hand, as will be discussed later, the smaller the molecular weight difference between R and X, the smaller the molecular weight difference between the tin compound (Al) and the impurities, which sometimes makes purification more difficult.

[0247] <Tin compound (B1)>

[0248] The tin compound (B1) of RSnX2Y is defined as follows: it is a compound bonded to tetravalent tin with one organic group R, two hydrolytic groups X capable of hydrolysis and other reactions, and one hydrolytic group Y. Specifically, it is represented by the following general formula (B1).

[0249] RSnX2Y ···(B1)

[0250] In the above general formula (B1), R is an organic group having 1 to 30 carbon atoms. Examples of such organic groups include haloalkyl groups; hydrocarbon groups containing heteroatoms such as oxygen and nitrogen atoms; and hydrocarbon groups. Two or more of these can be used together. X has the same meaning as shown above. X and Y are hydrolyzable groups with different chemical formulas, selected from OR'. B NR' B 2. C≡CR' B The above R' B An organic group having 1 to 10 carbon atoms, such as a haloalkyl group; a hydrocarbon group containing heteroatoms such as oxygen or nitrogen atoms; or a hydrocarbon group. Where X and / or Y are NR'. B In case 2, the above R'B They can be the same or different independently. Additionally, R' in the molecule... B When two or more structures exist, they can be different from each other or bonded together to form a ring structure.

[0251] Tin compounds (B1) are formed by two hydrolyzable groups X and one hydrolyzable group Y, and therefore can undergo hydrolysis at non-equivalent rates. Furthermore, by controlling the hydrolysis process, it is possible to preferentially react only with specific substituents X and / or Y.

[0252] As a preferred structure for RSnX2Y(B1), from the viewpoint of hydrolysis reactivity, it is preferable that X is NR2 and Y is NR'. B The structure of 2, especially considering the difference between X and Y during hydrolysis, preferably has Y as N(R'). B )CHNR' B 2.

[0253] [Tin hydrolysates containing tin compounds (A1) and (B1)]

[0254] RSnX3 and RSnX2Y can be hydrolyzed separately to form tin hydrolysates. In particular, to control crystallinity without reducing the purity of the obtained tin hydrolysates, a mixture containing (A1) and (B1) is preferred. That is, importantly, tin compounds (A1) and (B1) have the same organic group R, and the organic group R remaining in the tin hydrolysates after hydrolysis is substantially equivalent, which is different from the impurities contained in monoalkyltin compounds with structures different from (B1).

[0255] Regarding the composition (purity of tin compounds (A1) and (B1) in the specific mixture (A1B1) containing tin compounds (A1) and (B1), the lower limit of the purity of tin compound (A1) is preferably 10 mol% or more, more preferably 20 mol% or more, further preferably 30 mol% or more, particularly preferably 50 mol% or more, and especially preferably 70 mol% or more. The upper limit is preferably 99 mol% or less, more preferably 97 mol% or less, further preferably 95 mol% or less, and especially preferably 90 mol% or less. The lower limit of the purity of (B1) is preferably 10 mol% or more, more preferably 20 mol% or more, further preferably 30 mol% or more, particularly preferably 50 mol% or more, and especially preferably 70 mol% or more. The upper limit is preferably 99 mol% or less, more preferably 97 mol% or less, further preferably 95 mol% or less, and especially preferably 90 mol% or less. The total value of tin compounds (A1) and (B1) in the mixture (A1B1) is preferably 80 mol% or more, more preferably 85 mol% or more, and even more preferably 90 mol% or more. By making the total value of tin compounds (A1) and (B1) sufficiently high, a tin hydrolysate with high purity can be obtained. Regarding the content of RSnX2Y when the total value of tin compounds (A1) and (B1) is 80 mol% or more, the lower limit is preferably 0.01 mol% or more, more preferably 0.1 mol% or more, even more preferably 0.5 mol% or more, particularly preferably 1 mol% or more, especially preferably 3 mol% or more, and even more preferably 5 mol% or more. The upper limit is preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 20 mol% or less, and especially preferably 15 mol% or less.

[0256] <Impurities>

[0257] [Tin compounds as impurities]

[0258] There are no particular limitations on tin compounds other than the aforementioned tin compounds (A1) and (B1). Representative tin compounds include, for example, the following tin compounds (A2) and (A3). Tin compounds (A2) and (A3) are difficult to separate because their structures and boiling points are similar to those of tin compound (A1), making them difficult to separate by distillation. Furthermore, they are produced during reactions, heating, and other processes through the decomposition of tin compound (A1).

[0259] ·R2SnX2 ····(A2)

[0260] SnX4 ····(A3)

[0261] Especially when the boiling points of tin compound (A1) and tin compound (A2) or (A3) are close, as shown below, separation by distillation is often difficult, making suppression during reaction and post-processing important. Regarding examples containing impurities with similar boiling points, namely tin compounds (A2) and (A3), it is preferable to suppress the content of tin compounds (A2) and (A3) after the reaction. The amount of tin compounds (A2) and (A3) contained in the synthetic tin compound (crude product) after the reaction is preferably 3 mol% or less, more preferably 2 mol% or less, further preferably 1 mol% or less, particularly preferably 0.5 mol% or less, especially preferably 0.3 mol% or less, and even more preferably 0.1 mol% or less, 0.05 mol% or less, and 0.03 mol% or less. The lower limit is 0 mol%.

[0262] (Boiling point of impurities)

[0263] The boiling point here is not limited to atmospheric pressure, but refers to the boiling point when compared under the same pressure, especially under the pressure during distillation. A close difference in boiling points means that the difference between the boiling points of tin compounds (A1) and (A2) is typically 50°C or less, preferably 30°C or less, more preferably 10°C or less, and even more preferably 5°C or less. The lower limit is 0°C.

[0264] Furthermore, when the molecular weights of R and X are close, the difference in boiling points is also close, or the intermolecular interactions become stronger, making separation difficult in most cases. The situation where the difference in molecular weights of R and X is close refers to a difference that is typically 30 or less, preferably 20 or less, more preferably 10 or less, and even more preferably 5 or less. The lower limit is 0.

[0265] As an example, the molecular weight difference between iPrSn(NMe2)3 (A1-1) and iPr2Sn(NMe2)2 (A2-1) is small (294 g / mol and 293 g / mol, respectively). The difference is only 1 g / mol, and since isopropyl and dimethylamino groups have very similar polarities, the boiling point difference between the tin compounds (A1-1) and (A2-1) is extremely small. Boiling point measurements of these compounds show a difference of less than 2 °C within a pressure range of 0.7–10 torr. Therefore, to obtain high-purity tin compound (A1-1), distillation with high separation capabilities is required.

[0266] The decomposition of tin compounds (A1) and their precursor tin compounds (hereinafter sometimes referred to as "starter tin compounds") (E1) due to side reactions during the reaction and subsequent post-processing steps becomes a problem. For example, there are sometimes disproportionation reactions between tin compounds (A1) and (E1) as shown in the following formula, which can be accelerated or inhibited by various reaction conditions.

[0267] In addition, sometimes light-based decomposition reactions occur, or the decomposition reaction is accelerated by light and heat. Furthermore, the presence of trace amounts of air, moisture, etc., can sometimes promote decomposition.

[0268] (Decomposition of tin compounds)

[0269] [Chemical Formula 6]

[0270] [Other impurities]

[0271] In addition, when the tin compound (A1) is RSn(NR2)3, the following tin compound (A4) is sometimes contained as an impurity in the synthesized tin compound.

[0272] ·RSn(NR')2(N(R')CHNR'2)···(A4)

[0273] Tin compounds (A4) are produced by the decomposition of tin compounds (A1), and their formation can be accelerated by heat or light and their combination. For example, when the tin compound (A1) is iPrSn(NMe2)3 (A1-1), the tin compound (A4) as an impurity sometimes produces iPrSn(NMe2)2(NMeCHNMe2) (A4-1), which has the following characteristics. 119 Sn-NMR spectroscopy, 1 Chemical shifts in H-NMR can be used for identification and quantification.

[0274] 119 Sn-NMR (223.8MHz; C6D6): δ-82ppm.

[0275] 1 H-NMR (600MHz; C6D6): δ3.37(s,2H,CH2),2.89(s,3H,Sn-NMe),2.86(s,12H,Sn-(NMe2)2),2.15(s,6H,NMe2),1.68(m,1H,iPr),1.33(s,6H,iPr).

[0276] [Chemical Formula 7]

[0277] It should be noted that when X is a dialkylamino group (NR'2) (here, R'2 is selected from methyl, primary alkyl, or secondary alkyl groups), the formation mechanism of the above compound RSn(NR')2(N(R')CH2NR'2) is not yet clear. However, it is speculated that structurally, the radical (·NR'2) generated by the removal of one of the three dialkylamino groups in the tin compound (A1) inserts into the adjacent CH bond of the nitrogen atom of another nearby compound (A1). That is, specifically, as shown in the examples, this compound can be generated by the heating- and light-based decomposition of the tin compound (A1).

[0278] Furthermore, RSn(NR')2(N(R')CH2NR'2) of the above compounds typically represents the case where R' is methyl, but in the case where R' is, for example, a primary alkyl group such as ethyl (here, R' is set as CH2R), the situation is different. 1 Compound (A1) is derived from RSnN(CH2R) 1 In the case represented by )3, compound (A4) is derived from RSn[N(CH2R 1 )2]2[N(CH2R 1 CHR 1 N(CH2R 1 )2] indicates.

[0279] Additionally, when R' is a secondary alkyl group such as isopropyl (where R' is set as RCHR) 2 R 3 ), that is, compound (A1) is composed of RSn[N(CHR 2 R 3 In the case represented by )2]3, compound (A4) is derived from RSn[N(CHR] 2 R 3 )2]2[N(CHR 2 R 3 )CR 2 R 3 N(CHR 2 R 3 )2] indicates.

[0280] Sometimes it also contains divalent tin compounds, SnX2 (A8). In the case where the tin compound (A1) is RSn(NR2)3, the following tin compounds (A8-1) can be listed.

[0281] ·Sn(NR'2)2····(A8-1)

[0282] From the viewpoint of producing a high-purity photoresist material, the content of tin compound A8 is preferably 1.0 mol% or less, more preferably 0.5 mol% or less, even more preferably 0.1 mol% or less, and particularly preferably 0.01 mol% or less, relative to the content of the synthetic tin compound in terms of tin atoms. The lower limit is 0 mol%.

[0283] In addition, depending on the raw materials and manufacturing methods used, impurities such as R3SnX and R4Sn, which are tin compounds with more hydrocarbon groups, may also be mixed in as impurities.

[0284] <Method for manufacturing tin compound (A1)>

[0285] There is no particular limitation on the method for manufacturing tin compound (A1), and it can be manufactured by methods known in the past. Specifically, as a method for manufacturing a tin compound containing tin compound (A1) as the main component for the purpose of obtaining tin compound (A1), the following manufacturing methods can be listed as examples.

[0286] (Manufacturing Method 1)

[0287] As an example of a method for producing tin compound (A1), the following method can be described: a raw tin compound (E1) and a reactant ((M1) or (M2)) are reacted under specific conditions in an organic solvent (S1), thereby synthesizing a synthetic tin compound (A1). The following is a detailed description; in this manufacturing method, a typical reaction formula is shown below.

[0288] RSnY E 3(E1)+3MX(M1)→RSnX3(A1)+3MY E

[0289] This manufacturing method 1 can process the tin compound RSnY as a raw material. E 3. Purification can improve the purity and yield high-purity RSnX3(A1), which is preferred in this respect. In addition, from the viewpoint of using tin compounds with pre-introduced organic groups R as raw materials, it is possible to reduce the presence of tin compounds A2, A3, A4, etc., as impurities, and to reduce impurities that are difficult to separate during distillation, compared with other methods.

[0290] The following describes the material composition and other aspects used in the manufacturing method of tin compound (Al).

[0291] [Reference Tin Compound (E1)]

[0292] The raw material tin compound (E1) is represented by the following formula.

[0293] ·RSnY E3 ···(E1)

[0294] (In general formula (E1), R is an organic group having 1 to 30 carbon atoms. Examples of such organic groups include haloalkyl groups; hydrocarbon groups containing heteroatoms such as oxygen and nitrogen atoms; and hydrocarbon groups. Y) E Selected from halogen atoms, OR', and NR'2. R' can be the same or different, and is an organic group with 1 to 10 carbon atoms that can be substituted by halogens. Furthermore, when there are two or more R's in a molecule, their structures can be different from each other, or they can be bonded together to form a cyclic structure.

[0295] The organic group Y in the reaction formula E There are no restrictions on the structure as long as the organic group is substituted by the reactant (M1). As a preferred specific example, the organic group is selected from halogen atoms, OR', and NR'2. Among them, halogen atoms have high reactivity and are therefore preferred. Among them, Cl atoms have a good balance between stability and reactivity, are easy to purify by distillation, and are easy to prepare raw tin compounds (E1) with higher purity, and are therefore preferred. Among them, monoalkyltin chloride is the most preferred.

[0296] raw material tin compound RSnY E 3. Purity can be improved through purification. From the perspective of fewer residual impurities and increased high-purity tin compounds (Al), high-purity RSnY is preferred. E 3 is used as a raw material. Specifically, in terms of tin atoms, it is typically 95 mol% or more, preferably 97 mol% or more, more preferably 99 mol% or more, even more preferably 99.5 mol% or more, and particularly preferably 99.9 mol% or more. The upper limit is 100 mol%.

[0297] On the other hand, tin compounds and moisture, as impurities, can sometimes help prevent the crystallization of the target material and other stabilization processes, or affect the reaction of synthesizing tin compounds (Al). Sometimes it is preferable to contain 0.1 mol% or more of tin compounds as impurities, sometimes more preferably 0.2 mol% or more, and even more preferably 0.3 mol% or more.

[0298] Specifically, R2SnY E 2. R3SnY E The content of R2SnY, calculated in terms of tin atoms, is preferably 3 mol% or less, more preferably 2 mol% or less, even more preferably 1 mol% or less, and particularly preferably 0.1 mol% or less. On the other hand, from the viewpoint of helping to prevent stabilization such as crystallization of the target material, R2SnY is sometimes preferred. E 2. R3SnY E R4Sn contains 0.01 mol% or more, and sometimes more preferably 0.1 mol% or more.

[0299] [Reactant (M1)]

[0300] The reactant (M1) is a tin compound (E1)(RSnY) that can react with the raw material. E 3) Organic group Y E The reactant is capable of undergoing a substitution reaction and generating the tin compound (A1) (RSnX3) as the target. Preferred structures for the reactant (M1) include MX, MX2, MX3, etc. For example, when the reactant (M1) is MX, the theoretical reaction formula is as follows.

[0301] ·RSnY E 3(E1)+3MX(M1)→RSnX3(A1)

[0302] In the reaction formula, M represents a metal atom from Group 1, Group 2, Group 12, or Group 13. When M is from Group 1, it is sometimes represented as "MX"; when M is from Group 2 or Group 12, it is sometimes represented as "MX2"; and when M is from Group 13, it is sometimes represented as "MX3". The two or more X's in the molecule can also be different. Furthermore, X is as described above. Specifically, when X is OR', examples include LiOR', NaOR', KOR', MgOR'2, and ZnOR'2. From the viewpoint of high reactivity, LiOR', NaOR', and KOR' are preferred. When X is NR'2, LiNR'2, NaNR'2, KNR'2, Mg(NR'2)2, Zn(NR'2)2, etc. can be listed. From the viewpoint of high reactivity, LiNR'2, NaNR'2, and KNR'2 are preferred. From the viewpoint of stability, Mg(NR'2)2 and Zn(NR'2)2 are preferred. Among them, from the viewpoint of ease of preparation of high-purity reagents, LiNR'2 (aminolithium: dimethylaminolithium, diethylaminolithium, etc.) is the most preferred.

[0303] [Reactant (M2)]

[0304] The reactant (M2) refers to a compound selected from reactant (M1) or a compound represented by the chemical formula HX. H represents a hydrogen atom, and X has the same meaning as the X contained in the tin compound (A1). Examples of compounds equivalent to HX include HOR' (methanol, ethanol, tert-butanol, 4-methyl-2-pentanol, etc.) and HNR'2 (dimethylamine, diethylamine, morpholine, etc.). From the viewpoint of reactivity, compounds selected from reactant (M1) are preferred in reactant (M2) due to their high reactivity. From the viewpoint of preventing the introduction of metals after the reaction, compounds equivalent to HX, namely HOR' (methanol, ethanol, tert-butanol, 4-methyl-2-pentanol, etc.) and HNR'2 (dimethylamine, diethylamine, morpholine, etc.), are preferred, especially when the starting material tin compound (E1) (RSnY) is used. E 3)YE When the highly reactive NR'2 is used, it is sometimes possible to provide a high-purity product without the inclusion of metals if a compound equivalent to HX is used.

[0305] (Amounts of reactants (M1) and (M2))

[0306] The lower limit of the molar equivalent is preferably 3.00 eq or more, more preferably 3.03 eq or more, and most preferably 3.06 eq or more, relative to the raw material tin compound (E1).

[0307] The upper limit is preferably 10.00 eq or less, more preferably 8.00 eq or less, and even more preferably 7.00 eq or less. In addition, sometimes two or more reactants (M1) and (M2) are used together. In this case, the total molar equivalents of the reactants preferably fall within this range.

[0308] (Preparation method of reactant (M1))

[0309] Regarding the temperature of the process for preparing the reactant (M1), the preferred lower limit temperature is preferably about -78°C or higher, more preferably about -40°C or higher, even more preferably about -20°C or higher, particularly preferably about -10°C or higher, and especially preferably -5°C or higher. The upper limit temperature is preferably about 40°C or lower, more preferably about 20°C or lower, and even more preferably about 15°C or lower. Especially when the reactant (M1) is lithium amide, it needs to be prepared from an amine and an alkyl lithium. If the temperature is below the above upper limit, it is preferable to suppress the volatilization of the amine and the decomposition of the alkyl amide. In addition, if the temperature is above the above lower limit, it is preferable that the dimethylamide has excellent solubility in the solvent and excellent stirability due to its moderate viscosity.

[0310] The reaction time following the dropwise addition of the reactant (M1) is preferably 0.5 hours or less (sometimes referred to as "h"), more preferably 1 hour or more, and even more preferably 2 hours or more. The upper limit is preferably 48 hours or less, more preferably 30 hours or less, and even more preferably 20 hours or less. If the above reaction time is too short, the reactant (M1) may not be of sufficient purity, or, in the case of a slurry, insufficient mixing may result in an unevenly mixed reactant (M1). Conversely, if the above reaction time is too long, byproducts may be generated due to the decomposition of the reactant (M1), or the amount of reactant may be reduced by an equal amount.

[0311] In addition, from the perspective of maintaining the purity of the reactant (M1) or controlling the moisture content in the reactant (M1), it is preferable to continue stirring after the preparation of the reactant (M1) and use the reactant (M1) in this reaction during a period of 3 to 48 hours after preparation.

[0312] (Preparation method of reactant (M2))

[0313] Reagent (M2) refers to a compound selected from reactant (M1) or a compound represented by the chemical formula HX. The preparation method of reactant (M1) is as described above. Regarding the compound represented by the chemical formula HX, the following applies. Commercially available compounds of the chemical formula HX can be used directly; however, to avoid the introduction of impurities, moisture, or metals, it is preferable to use compounds that have undergone purification operations such as distillation, adsorption, or column chromatography. Alternatively, commercially available products have undergone purification operations such as semiconductor grade (EL grade) or dehydration grade. Specifically, the purity, on a mass basis, is preferably 95% or more, more preferably 98% or more, further preferably 99% or more, particularly preferably 99.99% or more, and especially preferably 99.99% or more. The upper limit is 100%. Preferred organic solvents for preparation are as shown in the following organic solvent (S1). Specifically, the amount of metal contamination, on a mass basis, is preferably 100 ppm or less for each metal element, more preferably 10 ppm or less, further preferably 1 ppm or less, especially preferably 100 ppb or less, and especially preferably 10 ppb or less. The lower limit is 0 ppb.

[0314] [Organic solvent (S1)]

[0315] In this manufacturing method, a tin compound (E1), a reactant ((M1) or (M2)), and an organic solvent (S1) are used. The organic solvent (S1) is not particularly limited, but preferably includes, for example, hydrocarbon solvents (hexane, cyclohexane, heptane, decane, decahydronaphthalene, etc.), aromatic solvents (benzene, toluene, xylene, anisole, etc.), ether solvents (THF (tetrahydrofuran), diethyl ether, TBME (tert-butyl methyl ether), dibutyl ether, 3-methylTHF, THP (tetrahydropyran), 3-methylTHP, etc.), ketone solvents (acetone, MEK (methyl ethyl ketone), MIBK (methyl isobutyl ketone), etc.), amide solvents (DMF (N,N-dimethylformamide), DMAC (N,N-dimethylacetamide), etc.), ester solvents (ethyl acetate, butyl acetate, etc.), and alcohol solvents (methanol, ethanol, isopropanol, butanol, 4-methyl-2-pentanol, etc.). Aromatic, hydrocarbon, and ether solvents that do not readily react with the reactant are preferred. These solvents can be used alone or in combination of two or more. The solvents are preferably those that do not contribute to the removal of metallic contaminants.

[0316] Hydrocarbons and aromatics, particularly those with low solubility in inorganic salts and readily removable byproducts such as inorganic salts after the reaction via filtration or centrifugation, are especially preferred solvents. Toluene and hexane are currently the most preferred solvents for easy removal of products under low temperature and vacuum after the reaction. On the other hand, ethers are preferred solvents for facilitating the reaction due to the high solubility of organometallic reactants such as lithium dimethylamino. In other words, combining two or more solvents, such as hydrocarbons, aromatics, and ethers, can sometimes combine the advantages of these solvents. Furthermore, when using HOR' (methanol, ethanol, tert-butanol, 4-methyl-2-pentanol, etc.) or HNR'2 (dimethylamine, diethylamine, morpholine, etc.) as reactants (M2), reactant (M2) sometimes also functions as a solvent.

[0317] (Manufacturing Method 2)

[0318] As an example, it is synthesized using SnX4, a tin compound, as a raw material, and RM or RMZ, a reactant containing R.

[0319] SnX4+RM→RSnX3+MX

[0320] SnX4+RMZ → RSnX3+MXZ E

[0321] In the above reaction formula, M represents a metal atom or a hydrogen atom from Group 1, Group 2, Group 12, or Group 13. When M is Group 1 or a hydrogen atom, it is sometimes represented as "RM"; when M is Group 2 or Group 12, it is sometimes represented as "RMZ". E When M is a family of 13, it is sometimes represented as "RMZ". E 2”, the two or more X’s in the molecule can also be different. Z E Represents a halogen atom or R. Two or more Z atoms in a molecule. E They can also be different. Additionally, X is as described above. Specifically, when X is OR', examples include ROH, RLi, RNa, RK, and RMGZ. E 、RZnZ E From the perspective of high reactivity, RLi is preferred; from the perspective of reactivity selectivity of monoalkylation, low basicity, and prevention of decomposition of the target analyte, RMgZ is preferred. E 、RZnZ E Among these, RMgZ is particularly preferred. Furthermore, from the viewpoint of not contaminating metals, ROH is preferred.

[0322] From the perspective of the reaction mechanism, this method has the problem of introducing byproducts with two or more organic groups R. Regarding this, the structure of RSnX3(A1) that is effective for this method is a structure where the organic group R is a tertiary alkyl group (e.g., tert-butyl, tert-pentyl, 1-methyl-cyclopentyl, 1-methyl-cyclohexyl). In this case, considering the ease of controlling the reactivity of the reactant RM and the difficulty of introducing two or more large tertiary alkyl groups onto the Sn atom, it tends to yield a good yield of the target product selectively added to one alkyl group. Furthermore, the fact that the boiling points of byproducts with two or more organic groups R differ significantly from those of the target product, making them easier to separate by distillation, also contributes to the effectiveness of this method.

[0323] (Manufacturing Method 3)

[0324] As an example, it includes step α, which involves producing MSnX3 from SnX2, a monoalkyltin compound used as a raw material, and a reactant containing MX, and then reacting the resulting MSnX3 with an alkylating agent RZ. F The reaction process β method.

[0325] SnX2+MX→MSnX3 (Process α)

[0326] MSnX3+RZ F →RSnX3 (Process β)

[0327] In the reaction formula, M represents a metal atom from Group 1, Group 2, Group 12, or Group 13. When M is from Group 1, it is sometimes represented as "MX"; when M is from Group 2 or Group 12, it is sometimes represented as "MX2"; and when M is from Group 13, it is sometimes represented as "MX3". Two or more X's in the molecule can also be different. Furthermore, X is as described above. Specifically, when X is OR', examples include LiOR', NaOR', KOR', MgOR'2, ZnOR'2, etc., with LiOR', NaOR', and KOR' being preferred from the viewpoint of high reactivity. When X is NR'2, examples include LiNR'2, NaNR'2, KNR'2, Mg(NR'2)2, Zn(NR'2)2, etc., with LiNR'2, NaNR'2, and KNR'2 being preferred from the viewpoint of high reactivity. Among these, LiNR'2 is the most preferred from the perspective of ease of preparing high-purity reagents. In the alkylating agent RZ... F In the middle, Z F The atoms are halogen atoms (F, Cl, Br, I), among which Br and I are preferred from the viewpoint of reactivity.

[0328] Starting from the reaction form, this method has the ability to synthesize or obtain alkyl halides, i.e., RZ. FAdvantages of introducing an organic group R. This is effective when applied to manufacturing methods 1 or 2, especially when the organic group R is unstable and causes decomposition or side reactions. Specifically, it is sometimes effective when the organic group R has heteroatoms, unsaturated bonds, aromatic rings, etc.

[0329] (Distillation purification)

[0330] Synthesized tin compounds (A1) (crude products) are sometimes further purified by distillation. The substance obtained by distillation and purification of the crude product is called purified tin compound (A1).

[0331] The higher the proportion of tin compound (Al) in the purified tin compound, the better the performance of the resist. Therefore, the purity of the tin compound (Al) is preferably 96 mol%, more preferably 97 mol%, further preferably 98 mol% or more, particularly preferably 99 mol% or more, especially preferably 99.2 mol% or more, particularly preferably 99.5 mol% or more, even more preferably 99.8 mol% or more, and most preferably 99.9 mol% or more. On the other hand, if the purity of the triaminotin compound is too high, it may decompose or become unstable during storage or use due to the disproportionation reaction of the organic group R of the tin compound (Al). In this case, it is preferable to be 100.0 mol% or less, more preferably 99.9 mol% or less.

[0332] For use as a photoresist material, the inorganic impurities in the purified tin compound are preferably low. Specifically, the elemental concentration of each inorganic impurity is preferably 10 ppm or less, more preferably 1 ppm or less, further preferably 0.1 ppm or less, and particularly preferably 0.01 ppm or less. The lower limit is 0 ppm.

[0333] It should be noted that when the purified tin compound does not reach sufficient quality, other purification processes are sometimes performed before and after distillation (purification using filtration or column chromatography, addition of adsorbents, reactants, etc.).

[0334] <<Applications as a corrosion-resistant material>>

[0335] <Method for manufacturing tin hydrolysate>

[0336] As a method for manufacturing this tin hydrolysate, hydrolysis is preferably carried out through the following steps.

[0337] <Step 1> Two or more precursors RSnX3(A1) with different structures of the above organic group R are combined to obtain a precursor mixture.

[0338] <Step 2> Contact the above precursor mixture with the organic solvent complex in liquid water.

[0339] In step 1 above, two or more precursors, i.e., a precursor mixture, are obtained. In this step, the precursor mixture is not hydrolyzed, and its chemical structure remains unchanged. Regarding the precursors, it is preferable to obtain a precursor mixture by, for example, converting it to a gaseous and / or liquid state and mixing it until it is sufficiently homogeneous; this precursor mixture is used in step 2. Therefore, it is preferable to carry out step 1 under an inert gas atmosphere. In steps 1 and 2, other solvents or additives may not be used, especially when the substance obtained by homogenizing the precursor mixture (step 1) as a liquid is combined with an organic solvent and the combination is reacted (mixed) with liquid water (step 2). It is preferable to prepare a composition by combining 100 parts by mass or more of an organic solvent relative to 100 parts by mass of the precursor mixture.

[0340] In step 1 above, in order to obtain a uniformly mixed precursor mixture, step 1 is preferably carried out by the following apparatus and mixing conditions.

[0341] The tin composition (M) obtained from the mixture under the preferred mixing conditions shown below results in a tin composition with a low proportion of tin compounds (P3A) and (P3B) having only a single organic group R, and a more uniform composition and molecular weight distribution. This is preferred from the aspects of reducing dissolution residue in resist solvents and improving filterability. In addition, it can suppress crystallization during storage and improve storage stability, which is also preferred.

[0342] On the other hand, when two or more precursors are not sufficiently and uniformly mixed before entering step 2 and undergoing hydrolysis, the precursors sometimes hydrolyze in an unbalanced state. This results in a decrease in the percentage of each tin compound (P3AB) in the tin composition (M), or an increase in the proportion of tin compounds (P3A) and (P3B) having only a single organic group R. Furthermore, the distribution shape of the curve plotted with the percentage of each tin compound (P3AB), (P3A), and (P3B) in the tin composition (M) as the y-axis and the number of organic groups R in a molecule as the x-axis sometimes exhibits a more uneven distribution, with two or more peaks. Additionally, the molecular weight distribution in the tin composition (M) tends to broaden.

[0343] <Apparatus and conditions for mixing>

[0344] The container used for mixing in step 1 is not particularly limited. However, it is preferable to use a container equipped with a stirring device and to perform mixing under conditions that do not cause decomposition of the precursor or contamination of impurities. Specifically, preferred containers for mixing are glass containers, SUS containers, Teflon (registered trademark) containers, and containers made of their composite materials, all equipped with a stirring device. Containers with a glass inlet surface are particularly preferred as they prevent the contamination of metal components and minimize the decomposition of the precursor. As for the stirring device, a blade-type rotary stirring device such as a stirring blade or stir bar (magnetic stirrer) is preferred because it can efficiently stir the liquid mixture. Furthermore, when these containers and stirring devices are thoroughly cleaned with ultrapure water and then thoroughly dried, the contamination of metal components and halogens is minimal. The rotational speed of the stirring device is preferably 50 rpm or higher, preferably 100 rpm or higher, preferably 150 rpm or higher, and more preferably 200 rpm or higher. Within these preferred speed ranges, a homogeneous mixture can be prepared in a short time without decomposition, which is also preferable. As for the mixing time, there is no particular limitation as long as the mixing is sufficiently and uniformly within a time range that does not cause precursor decomposition. The upper limit is preferably within 12 hours, more preferably within 6 hours, further preferably within 3 hours, particularly preferably within 1 hour, and especially preferably within 30 minutes. The lower limit is preferably 1 minute or more, more preferably 2 minutes or more, and further preferably 5 minutes or more.

[0345] The mixing temperature is not particularly limited, but the upper limit is preferably below 150°C, more preferably below 100°C, further preferably below 50°C, and particularly preferably below 30°C. The lower limit is preferably above -20°C, more preferably above -10°C, and further preferably above -5°C. If the mixing temperature is below the above upper limit, the generation of impurities and insoluble substances caused by the decomposition of precursors during mixing can be suppressed, or the non-uniformity caused by the volatilization of precursors and solvents can be suppressed. In addition, if the temperature is above the above lower limit, the precursors will not crystallize or dissolve, and they can be mixed uniformly in a liquid state.

[0346] Furthermore, nitrogen or argon is preferred as the inert gas used to fill the container during mixing, and high-purity nitrogen or argon is even more preferred. Additionally, since the precursor compound may react with light and decompose, producing impurities and insoluble substances, mixing is preferably carried out under light-shielding conditions.

[0347] <Solvent during mixing in step 1>

[0348] During the mixing in step 1, a solvent is not necessarily required as long as the target precursor mixture can be obtained. However, using an organic solvent may allow for more efficient mixing. Furthermore, if the same solvent as that used during hydrolysis in the subsequent step 2 is used, a solvent replacement step is not required, which is therefore preferable. The specific organic solvent is not particularly limited, but preferably includes, for example, hydrocarbon solvents (hexane, cyclohexane, heptane, decane, decahydronaphthalene, etc.), aromatic solvents (benzene, toluene, xylene, anisole, etc.), ether solvents (THF (tetrahydrofuran), diethyl ether, TBME (tert-butyl methyl ether), dibutyl ether, 3-methylTHF, THP (tetrahydropyran), 3-methylTHP, etc.), ketone solvents (acetone, MEK (methyl ethyl ketone), MIBK (methyl isobutyl ketone), etc.), amide solvents (DMF (N,N-dimethylformamide), DMAC (N,N-dimethylacetamide), etc.), esters (ethyl acetate, butyl acetate, etc.), halogen solvents (dichloromethane, chloroform), alcohol solvents (methanol, ethanol, isopropanol, butanol, 4-methyl-2-pentanol, etc.), and preferably combinations of solvents that do not react with the precursor used. Specifically, in highly reactive systems where the precursor structure includes NR2 groups, aprotic solvents are preferred. Aprotic solvents are specifically aromatic, hydrocarbon, ether, and halogen solvents. These solvents can be used alone or in combination of two or more. The solvent is preferably one that does not contribute to the removal of metallic contaminants. Furthermore, the water content in the solvent is preferably 100 ppm or less, more preferably 50 ppm or less, more preferably 30 ppm or less, and even more preferably 15 ppm or less, to prevent hydrolysis during mixing. The lower limit is 0 ppm.

[0349] It should be noted that, in order to obtain a gaseous precursor mixture in step 1, there are the following methods: placing a substance pre-mixed with two or more precursors into a container and allowing it to evaporate as a precursor mixture; or mixing the vapors of two or more precursors in a device such as a CVD or ALD apparatus (including auxiliary mixing devices, piping, etc.). From the viewpoint of reproducible and uniform mixing of precursors with different boiling points, a method of mixing in the location where step 2, in which hydrolysis is performed, is more preferred, i.e., mixing in a device such as a CVD or ALD apparatus (including auxiliary mixing devices, piping, etc.).

[0350] Next, in the case of hydrolysis using liquid water, it is preferable to prepare two or more precursors or a precursor mixture under an inert gas atmosphere (step 1), and then contact the mixture with a complex of an organic solvent in liquid water to hydrolyze the precursor mixture (step 2). In this case, the organic solvent used in step 2 is preferably a solvent that does not hydrolyze the precursors; specifically, an aprotic solvent is preferred, and a dehydrated aprotic solvent is even more preferred.

[0351] [Organic solvents during hydrolysis]

[0352] In this manufacturing method, there are no particular limitations on the organic solvent, but preferred organic solvents include, for example, hydrocarbon solvents (hexane, cyclohexane, heptane, decane, decahydronaphthalene, etc.), aromatic solvents (benzene, toluene, xylene, anisole, etc.), ether solvents (THF (tetrahydrofuran), diethyl ether, TBME (tert-butyl methyl ether), dibutyl ether, 3-methylTHF, THP (tetrahydropyran), 3-methylTHP, etc.), ketone solvents (acetone, MEK (methyl ethyl ketone), MIBK (methyl isobutyl ketone), etc.), amide solvents (DMF (N,N-dimethylformamide), DMAC (N,N-dimethylacetamide), etc.), esters (ethyl acetate, butyl acetate, etc.), halogen solvents (dichloromethane, chloroform), and alcohol solvents (methanol, ethanol, isopropanol, butanol, 4-methyl-2-pentanol, etc.), preferably combinations of solvents that do not react with the precursor used. Specifically, in highly reactive systems where the precursor structure includes NR2 groups, aprotic solvents are preferred. Aprotic solvents are specifically aromatic, hydrocarbon, ether, and halogen solvents. These solvents can be used alone or in combination of two or more. The solvent is preferably one that does not contribute to the removal of metallic contaminants. Furthermore, the water content in the solvent is preferably 100 ppm or less, more preferably 50 ppm or less, more preferably 30 ppm or less, and even more preferably 15 ppm or less, to prevent uneven hydrolysis before water is added. The lower limit is 0 ppm.

[0353] <Apparatus and conditions for hydrolysis>

[0354] The apparatus and container used for hydrolysis in step 2 are not particularly limited. However, it is preferable to use a container equipped with a stirring device and to carry out the hydrolysis without causing decomposition of the precursor or contamination of impurities. Specifically, preferred containers for hydrolysis include glass containers, SUS containers, Teflon containers, and containers made of composite materials of these materials, all equipped with a stirring device. Containers with a glass inlet surface are particularly preferred as they prevent the contamination of metal components and minimize the risk of precursor decomposition. As for the stirring device, a blade-type rotary stirring device such as a stirring blade or stir bar (magnetic stirrer) is preferred because it can efficiently stir the liquid mixture. Furthermore, when these hydrolysis containers and stirring devices are thoroughly cleaned with ultrapure water and then thoroughly dried, the contamination of metal components and halogens is minimal. The rotational speed of the stirring device is preferably 50 rpm or higher, preferably 100 rpm or higher, preferably 150 rpm or higher, and more preferably 200 rpm or higher. Within these preferred speed ranges, a uniform hydrolysis reaction can be carried out in a shorter time, which is also preferable. As for the mixing time, there is no particular limitation as long as the mixing is sufficiently uniform within a time range that does not cause the precursor to decompose. The upper limit is preferably within 12 hours, more preferably within 6 hours, further preferably within 3 hours, particularly preferably within 1 hour, and especially preferably within 30 minutes. The lower limit is preferably 1 minute or more, more preferably 2 minutes or more, and further preferably 5 minutes or more. There is no particular limitation on the temperature during hydrolysis. The upper limit is preferably 150°C or less, more preferably 100°C or less, further preferably 50°C or less, and particularly preferably 30°C or less. The lower limit is preferably -20°C or more, more preferably -10°C or more, and further preferably -5°C or more. If the mixing temperature is below the above upper limit, it tends to suppress the generation of impurities and insoluble substances caused by the decomposition of the precursor during mixing, or to suppress unevenness caused by the volatilization of the precursor and solvent. In addition, if it is above the above lower limit, it tends to prevent the precursors from crystallizing or dissolving, and can be uniformly mixed in a liquid state.

[0355] Furthermore, nitrogen or argon is preferred as the inert gas used to fill the container during hydrolysis, and high-purity nitrogen or argon is even more preferred. Additionally, since the precursor compound may react with light and decompose, producing impurities and insoluble substances, mixing is preferably performed under light-shielding conditions.

[0356] <Method for forming thin films containing tin hydrolysate>

[0357] The tin hydrolysate (P1) shown above can be used as a photoresist material. Regarding its use as a photoresist material, the method disclosed in Japanese Patent Application Publication No. 2021-21953 can be used, for example. For its use as a photoresist material, methods for forming a thin film (coating layer, film, etc.) containing the tin hydrolysate on a substrate include, for example, the following dry and wet methods.

[0358] In the dry process, a monoalkyltin compound (precursor) used as a raw material for tin hydrolysate is volatilized under heating and reduced pressure and used as vapor. Water vapor, other gases, etc., react with the vapor of the precursor or the precursor deposited onto the substrate to synthesize the tin hydrolysate. By implementing this method on the substrate, a thin film (coating film) containing the tin hydrolysate can be formed on the substrate. Depending on the needs, the formation of the tin hydrolysate may sometimes be promoted by combining reactions, heating, cleaning, etc., before and after this process.

[0359] In the wet process, a method is as follows: a raw material containing a monoalkyltin compound (precursor) as a raw material for tin hydrolysate is reacted with water or the like in a solution or solid state to perform hydrolysis, thereby obtaining tin hydrolysate. The tin hydrolysate can then be dissolved in an organic solvent or the like and used as a coating solution. Alternatively, sometimes a solution containing the precursor is first coated onto a substrate, and then part or all of the above hydrolysis process is applied to the substrate to generate the tin hydrolysate.

[0360] In the coating process, coating can be applied to the substrate using optional coating or printing techniques, or a thin film (coated film) containing tin hydrolysate can be formed on the substrate.

[0361] In the above-described wet film formation method, two cases can be listed: one where the formation of tin hydrolysates caused by hydrolysis in step 2 occurs before film formation and the other where it occurs after film formation. In both cases, in order to produce a tin composition (M) having two or more organic groups with appropriate composition and distribution, it is preferable to perform hydrolysis before film formation using the preferred method of hydrolysis in step 2 described above. When hydrolysis is performed before film formation, the reaction with water occurs uniformly while being appropriately mixed, thus enabling the synthesis of a more uniform tin composition (M). That is, during subsequent film formation, a more uniform tin composition (M) with a lower proportion of tin compounds (P3A) and (P3B) having only a single organic group R can be obtained, exhibiting a more uniform composition and molecular weight distribution.

[0362] On the other hand, when hydrolysis is performed after film formation, the hydrolysis occurs in a state of insufficient mixing due to the non-uniform film formation, resulting in an uneven tin composition (M). Specifically, examples include forming a film by coating the resist solution onto the substrate without hydrolysis and then hydrolyzing it with water or the like after film formation. In such cases, the content (%) of each tin compound (P3AB) in the tin composition (M) after hydrolysis may decrease, or the proportion of tin compounds (P3A) and (P3B) having only a single organic group R may increase. Furthermore, the distribution shape of a curve plotted with the content (%) of each tin compound (P3AB), (P3A), and (P3B) in the tin composition (M) of the film as the y-axis and the number of organic groups R in a molecule as the x-axis sometimes exhibits a more uneven distribution, with more than two peaks. Additionally, the molecular weight distribution in the tin composition (M) tends to broaden.

[0363] <Patterning of Thin Films>

[0364] The films obtained by any of the above methods are sometimes stabilized or partially condensed before light irradiation by drying, heating, etc. Typically, the films (coated films) are thin, for example, having an average thickness of less than 10 micrometers. To pattern very small features, very thin submicron films, such as those less than about 100 nm, then less than 50 nm, and especially less than 30 nm, are sometimes preferred. The resulting films (coated films) are treated by exposure in a manner that makes them resistant to development / etching as part of the composition, and therefore can be called "resist".

[0365] For thin films (coated films), exposing a selected pattern or the negative portion of a pattern to appropriate radiation, such as extreme ultraviolet light, electron beams, or ultraviolet light, can form a latent image with developer-resistant and developer-soluble regions. After exposure to appropriate radiation and before development, reacting the film by heating or other methods can differentiate the latent image from the unirradiated areas. The latent image contacts the developer, forming a physical image, i.e., a patterned film. Further heating of the patterned film can stabilize any remaining patterned film on the surface. The patterned film can be used as a physical mask for further processing according to the pattern, such as etching of the substrate and / or attachment of additional materials. After using the patterned film as a resist as desired, any remaining patterned film can be removed at an appropriate time during processing, but the patterned film can also be assembled into the final structure.

[0366] The conditions for each process are described in more detail below.

[0367] <Preparation and Filtration of Corrosion Resist Solution>

[0368] Typically, the resist solution used in the aforementioned wet process is prepared by thorough mixing using a suitable mixing apparatus appropriate for the volume of the material to be formed. Additionally, appropriate filtration can be used to remove any contaminants or other insoluble components. In some embodiments, the prepared resist solutions are sometimes used in combination. Furthermore, in addition to adding a tin compound as the main component, various additives may be added to the resist solution.

[0369] <Coating on substrate>

[0370] The precursor in the dry process and the resist solution in the wet process are appropriately selected based on their adhesion to the substrate and subsequent processability. The precursor in the dry process and the resist solution in the wet process can typically adhere to the substrate surface. Furthermore, the substrate may comprise two or more layers on its surface. In some embodiments, the substrate surface may be treated to allow the precursor in the dry process and the resist solution in the wet process to adhere. Additionally, the substrate surface may be cleaned and / or smoothed as needed. Suitable substrate surfaces may contain optional, appropriate materials. Several substrates of particular interest (e.g., silicon wafers, silicon dioxide substrates) contain other inorganic materials such as ceramic materials, polymer substrates, such as organic polymers, composites thereof, and combinations thereof on the substrate surface and / or within the substrate surface layers. Thin, circular wafers are convenient as substrates, but structures of optional, appropriate shapes can be used.

[0371] Substrates having polymer layers on polymer substrates or non-polymer structures are sometimes desirable for specific applications due to their low cost and flexibility. The polymer can be selected based on the relatively low processing temperatures that can be used when processing the patterned materials described in this specification. Preferably, the polymer comprises, for example, polycarbonate, polyimide, polyester, polyolefin, copolymers thereof, and mixtures thereof.

[0372] Typically, especially for high-resolution applications, the substrate preferably has a flat surface. However, in certain embodiments, the substrate sometimes has a substantial morphology, and for specific patterning applications, the resist coating is intended to fill or planarize the features. Such functionality of resist materials is described by reference in U.S. Patent Application Publication No. 2015 / 0253667 (Bristol et al.), entitled “Pre-Patterned Hard Mask for Ultrafast Lithographic Imaging”, cited in this specification.

[0373] Typically, to coat the precursor in a dry process and the resist solution in a wet process onto a substrate, an optional and suitable coating process can be used. As coating methods, in the case of a wet process, spin coating, spray coating, dip coating, blade coating, and printing methods (e.g., inkjet printing and screen printing) are preferred; as a dry process, vapor deposition methods such as physical vapor deposition and chemical vapor deposition are preferred. Some of these coating methods form patterns during the coating process, but the resolution obtained by printing, etc., is significantly lower than the resolution obtained by the radiation-based patterning described in this specification. To provide greater control over the coating process, the coating material can be applied in multiple coating steps. For example, performing spin coating twice or more in a wet process and vapor deposition twice or more in a dry process can achieve the desired final coating thickness. The heat treatment described below can be applied after each coating step or after two or more coating steps.

[0374] When using radiation to perform patterning, spin coating can be a preferred method for relatively uniformly covering the substrate, but edge effects may occur. In some embodiments, the wafer can be rotated at a speed of about 500 rpm to about 10,000 rpm, in further embodiments at a speed of about 1,000 rpm to about 7,500 rpm, and in additional embodiments at a speed of about 2,000 rpm to about 6,000 rpm. The rotation speed can be adjusted in a way that achieves the desired coating thickness. Spin coating can be performed in a time of about 5 seconds to about 5 minutes, and in further embodiments in a time of about 15 seconds to about 2 minutes. Using an initial low-speed rotation (e.g., 50 to 250 rpm), an initial overall coating of the composition can be performed on the entire substrate. To remove any edge welds, water or other suitable solvents can be used to perform backwashing, edge weld removal steps, etc. Those skilled in the art will understand that additional ranges of spin coating parameters within the above-defined ranges are included within the scope of this disclosure.

[0375] The thickness of a coated film typically tends to depend on the concentration, viscosity, and spin-coating speed of the resist solution in wet processes, and on the vapor deposition pressure in dry processes. In other coating processes, the thickness can generally be adjusted by selecting coating parameters. In some embodiments, a thin coating is sometimes desirable to facilitate the formation of small and highly customizable features in subsequent patterning processes. For example, the dried coated film may have an average thickness of less than about 10 μm, in other embodiments less than about 1 μm, in further embodiments less than about 250 nm, in additional embodiments from about 1 nm to about 50 nm, in other embodiments from about 2 nm to about 40 nm, and in some embodiments from about 3 nm to about 25 nm. Those skilled in the art will understand that additional ranges of thickness within the aforementioned defined ranges are included within the scope of this disclosure. Thickness can be evaluated using non-contact methods of X-ray reflectance and / or polarization analysis based on the film's optical properties. Generally, a relatively uniform coated film is preferred for ease of processing. In some embodiments, the variation in coating thickness is less than ±50% relative to the average coating thickness, in further embodiments less than ±40%, and in additional embodiments less than approximately ±25% relative to the average coating thickness. In some embodiments, such as coatings with high uniformity on larger substrates, the evaluation of coating uniformity can be performed excluding the 1 cm edge. That is, the uniformity of the coating is not evaluated for portions within 1 cm of the coating edge. Those skilled in the art will understand that additional ranges within the aforementioned defined ranges are included within the scope of this disclosure.

[0376] Two or more coating processes form coating materials with larger surface areas and / or stimulating evaporation of the solution, resulting in the evaporation of some of the solvent. Solvent evaporation tends to increase the viscosity of the coating material as the concentration of the species in the material increases. The goal during the coating process is to remove sufficient solvent or to react the active substances in the dry process precursor and the wet process resist solution to stabilize them for further processing. That is, between the coating step and the subsequent heating step, solvent may be removed, or hydrolysates of tin compounds may be formed, or condensation may occur. Typically, the dry process precursor and the wet process resist solution can be heated before exposure to radiation to promote densification. In the dried coating film, the dry process precursor and the wet process resist solution typically form a high-molecular-weight metal oxo / hydroxyl network based on metal oxo-hydroxyl ligands, where the metal also has a molecular solid composed of several hydrocarbon groups or polynuclear metal oxo / hydroxyl species with hydrocarbon groups.

[0377] In the case of wet processes, the solvent removal process can either quantitatively control a specific amount of solvent remaining in the coating material or not. Empirical evaluation of the properties of the resulting resist solution can usually be carried out in order to select processing conditions that are effective for the patterning process.

[0378] Heating is not required for successful process applications, but it is sometimes desirable to heat the coated substrate to accelerate processing and / or increase process reproducibility. In embodiments where heating is applied to remove solvents, the coated substrate with the coated film can be heated to about 45°C to about 250°C, and in further embodiments, it can be heated to about 55°C to about 225°C. Heating for solvent removal can typically be performed for at least about 0.1 minutes, in further embodiments for about 0.5 minutes to about 30 minutes, and in additional embodiments for about 0.75 minutes to about 10 minutes. Those skilled in the art will understand that additional ranges of heating temperature and time within the aforementioned defined ranges are included within the scope of this disclosure. As a result of heat treatment and densification, the coated film can exhibit an increase in refractive index and radiation absorption without significantly sacrificing contrast.

[0379] <Exposed Patterned and Patterned Coating Films>

[0380] The coated film can be finely patterned using radiation. As described above, depending on the composition of the resist solution, the composition of the corresponding coated film can be designed to sufficiently absorb radiation of the desired form. Radiation absorption generates energy that breaks the bonds between the metal and hydrocarbon groups, resulting in at least a portion of the hydrocarbon groups being unusable for material stabilization. Radiation decomposition products containing hydrocarbon groups or fragments may or may not diffuse from the film depending on process variables and the identity of such products. Through sufficient radiation absorption, the exposed coated film condenses, forming an enhanced metal oxo / hydroxyl network, which may contain water absorbed from the surrounding atmosphere. Radiation can typically be delivered according to the selected pattern. This radiation pattern is transferred into the coated film as a latent image with corresponding irradiated and non-irradiated areas. The irradiated areas tend to form a chemical change in the composition of the coated film. As described below, during development, by selectively removing the non-irradiated portions or selectively removing the irradiated portions from the coated film, a pattern with very sharp edges can be formed.

[0381] Radiation can typically be directed toward the substrate through a mask, or the radiation beam can be scanned across the entire substrate in a controlled manner. Typically, the radiation can include electromagnetic radiation, electron beams (beta radiation), or other suitable radiation. Electromagnetic radiation can typically have a desired wavelength or wavelength range, such as visible light, ultraviolet light, or X-rays. The resolution achievable for a radiation pattern generally depends on the wavelength of the radiation; higher resolution patterns are generally achieved with shorter wavelength radiation. Therefore, ultraviolet light, X-rays, or electron beams are sometimes preferred, especially for achieving high-resolution patterns.

[0382] According to the international standard ISO 21348 (2007), which is referenced in this specification, ultraviolet light extends across wavelengths greater than 100 nm and less than 400 nm. A krypton fluoride laser can be used as a 248 nm ultraviolet source. The ultraviolet region can be subdivided, within permissible standards, by various methods into extreme ultraviolet (EUV) light greater than 10 nm and less than 121 nm, and far ultraviolet (FUV) light greater than 122 nm and less than 200 nm, etc. A 193 nm line from an argon fluoride laser can be used as the radiation source in FUV. EUV light at 13.5 nm was used for photolithography, generated by a Xe or Sn plasma source excited using a high-energy laser or discharge pulse. Soft X-rays can be defined as greater than 0.1 nm and less than 10 nm.

[0383] The amount of electromagnetic radiation can be characterized by the flux, or dose, obtained from the integrated radiation flux relative to the exposure time. A suitable radiation flux can be approximately 1 mJ / cm². 2 ~ Approximately 150 mJ / cm 2 In a further embodiment, it can be approximately 2 mJ / cm². 2 ~ Approximately 100 mJ / cm 2 Furthermore, in a further embodiment, it can be approximately 3 mJ / cm³. 2 ~ Approximately 50 mJ / cm 2 Those skilled in the art will understand that additional ranges of radiation doses within the aforementioned defined range are included within the scope of this disclosure.

[0384] In electron beam lithography, the electron beam typically induces secondary electrons, which usually cause changes in the irradiated material. Resolution can be at least partially a function of the range of secondary electrons within the material. Here, higher resolution is generally considered to be achieved by a shorter range of secondary electrons. Based on the high resolution achievable by electron lithography using the inorganic coating materials described in this specification, the range of secondary electrons in the inorganic material is limited. The electron beam can be characterized by the energy of the beam, with suitable energies ranging from about 5V to about 200kV, and in further embodiments from about 7.5V to about 100kV. A proximity-corrected beam dose of 30kV can be approximately 0.1 μC / cm². 2 ~ Approximately 5mC / cm 2 The range, in a further embodiment, can be approximately 0.5 μC / cm. 2 ~ Approximately 1 mC / cm 2 The range, and in other embodiments, can be approximately 1 μC / cm. 2 ~ Approximately 100 μC / cm 2 The range is defined in this specification. Those skilled in the art can calculate the corresponding dose at other beam energies based on the teachings in this specification. It should be understood that additional ranges of electron beam characteristics within the aforementioned defined range are included within the scope of this disclosure.

[0385] Based on the design of the precursor in the dry process and the resist solution in the wet process, there is a significant contrast in material properties between the irradiated area and the non-irradiated area with substantially unchanged hydrocarbon groups in the coated film. Although the contrast of dosage can be improved by post-irradiation heat treatment, satisfactory results can be obtained even without post-irradiation heat treatment in some embodiments. It is believed that post-exposure heat treatment, which anneals the irradiated area, will not cause significant shrinkage of the non-irradiated area of ​​the coated film due to thermal breakdown of hydrocarbon-metal bonds, thus preventing increased shrinkage. In embodiments using post-irradiation heat treatment, the post-irradiation heat treatment can be carried out at a temperature of about 45°C to about 250°C, in additional embodiments at a temperature of about 50°C to about 190°C, and in further embodiments at a temperature of about 60°C to about 175°C. Post-exposure heating can typically be carried out for at least about 0.1 minutes, in further embodiments for about 0.5 minutes to about 30 minutes, and in additional embodiments for about 0.75 minutes to about 10 minutes.

[0386] Those skilled in the art will understand that additional ranges of post-irradiation heating temperatures and times within the aforementioned defined ranges are included within the scope of this disclosure. This high contrast in material properties facilitates the formation of sharp lines in the developed patterns described in the following sections. As a result, after exposure to radiation, the coating film is patterned through both irradiated and unirradiated areas.

[0387] <Development and Patterning Structures>

[0388] Image development includes: contacting a coating film containing a latent image with a developer composition to remove unexposed areas to form a negative image; or removing exposed areas to form a positive image. If the precursor in the dry method and the resist solution in the wet method described in this specification are used, effective negative or positive patterning with the desired resolution can generally be performed based on the same coating and using a suitable developer. In particular, there is a tendency for the exposed areas to at least partially condense, increasing the properties of the components constituting the coating film. As a result, the exposed areas are resistant to dissolution in organic solvents, while the unexposed areas remain soluble in organic solvents. The exposed areas further condense due to the cleavage of hydrocarbon-tin bonds, resulting in the release of hydrocarbon groups, and the metal oxide-like properties of the components constituting the coating film tend to increase. On the other hand, the unexposed material is hydrophobic due to the non-release of hydrocarbon groups, making it difficult to dissolve in weak alkaline or acidic aqueous solutions. Therefore, for positive patterning, an alkaline aqueous solution can be used to remove the exposed material while retaining the unexposed material.

[0389] Hydrocarbon-based precursors in dry processes and resist solutions in wet processes generate inherently hydrophobic materials. Irradiation, which breaks at least a portion of the organometallic bonds, transforms the material into a less hydrophobic, i.e., more hydrophilic material. This change in property provides a significant contrast between the irradiated and unirradiated areas of the coating film, thereby enabling both positive and negative patterning of the coating film. Specifically, the irradiated areas of the coating film condense to a certain extent into a composition with more metal oxides, but even without significant heating, the degree of condensation is typically moderate; therefore, the irradiated material is insoluble compared to conventional development using a developer.

[0390] In the case of negative image formation, the developer can be an organic solvent, such as the solvent used to form the resist solution. Typically, the choice of developer is influenced by solubility parameters related to the composition of the coated film (the chemical composition of the irradiated and unirradiated areas), as well as the developer's volatility, flammability, toxicity, viscosity, and potential chemical interactions with other process materials. In particular, suitable developers include, for example, aromatic compounds (e.g., benzene, xylene, toluene), esters (e.g., propylene glycol monomethyl acetate, ethyl acetate, ethyl lactate, n-butyl acetate, butyrolactone), alcohols (e.g., 4-methyl-2-pentanol, 1-butanol, isopropanol, 1-propanol, methanol), ketones (e.g., methyl ethyl ketone, acetone, cyclohexanone, 2-heptanone, 2-octanone), ethers (e.g., tetrahydrofuran, dioxane, anisole), etc. Development can be performed from about 5 seconds to about 30 minutes, in a further embodiment from about 8 seconds to about 15 minutes, and in an additional embodiment from about 10 seconds to about 10 minutes. Those skilled in the art will understand that additional scope within the aforementioned explicit scope is included within the scope of this disclosure.

[0391] In the case of positive image formation, the developer is typically an acidic or alkaline aqueous solution. In some embodiments, alkaline aqueous solutions can be used to obtain sharper images. To reduce contamination from the developer, it is sometimes desirable to use a developer that does not contain metal atoms. Therefore, as a developer, quaternary ammonium hydroxide compositions, such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or combinations thereof, are preferred. Generally, quaternary ammonium hydroxides of particular interest can be derived from formula R. 4 NOH (where R = methyl, ethyl, propyl, butyl, or a combination thereof) is used. The coating materials described in this specification can generally be developed using the same developers commonly used in polymer resists, specifically tetramethylammonium hydroxide (TMAH). Commercially available TMAH can be used at a concentration of 2.38% by mass, which is suitable for the treatments described in this specification. Alternatively, mixed tetraalkylammonium hydroxides can be used. Typically, the developer may contain about 0.5% by mass to about 30% by mass of tetraalkylammonium hydroxide or the same quaternary ammonium hydroxide; in further embodiments, it may contain about 1% by mass to about 25% by mass of tetraalkylammonium hydroxide or the same quaternary ammonium hydroxide; and in other embodiments, it may contain about 1.25% by mass to about 20% by mass of tetraalkylammonium hydroxide or the same quaternary ammonium hydroxide. Those skilled in the art will understand that additional ranges of developer concentrations within the aforementioned defined ranges are included within the scope of this disclosure.

[0392] In addition to the main developer composition, the developer may contain additional compositions to facilitate the developing process. Suitable additives include, for example, cations selected from the group consisting of ammonium, d-block metal cations (hafnium, zirconium, lanthanum, etc.), f-block metal cations (cerium, lutetium, etc.), p-block metal cations (aluminum, tin, etc.), alkali metals (lithium, sodium, potassium, etc.), and combinations thereof, and anions selected from the group consisting of fluorine, chlorine, bromine, iodine, nitric acid, sulfuric acid, phosphoric acid, silicic acid, boric acid, peroxides, butoxides, formic acid, oxalic acid, ethylenediaminetetraacetic acid (EDTA), tungstic acid, molybdic acid, etc., and combinations thereof. Other potentially useful additives include, for example, molecular chelating agents, such as polyamines, alkanolamines, amino acids, carboxylic acids, or combinations thereof. In the presence of optional additives, the developer may contain about 10% by mass or less of the additive, and in further embodiments, about 5% by mass or less of the additive. Those skilled in the art will understand that additional ranges of additive concentrations within the aforementioned defined ranges are included within the scope of this disclosure. Additives can be selected to improve contrast, sensitivity, and linewidth roughness. Additives in developers can also inhibit the formation and precipitation of metal oxide particles.

[0393] In the case of weaker developers, such as lower concentrations of aqueous developers, diluted organic developers, or compositions (where the coating has a lower development speed), a higher temperature development process can be used to increase the process speed. In the case of stronger developers, the temperature of the development process can be lowered to reduce the development speed and / or control the development kinetics. Typically, the development temperature can be adjusted to an appropriate value consistent with the solvent's volatility. Furthermore, the developer containing the coating film components dissolved near the developer-coating interface can be dispersed by ultrasonic treatment during development.

[0394] The developer can be applied to the coated film containing the latent image using any suitable means. For example, the developer can be sprayed onto the patterned coating material. Alternatively, spin coating can be used. In the case of automated processing, a spin-dip method can be used, which involves statically pouring the developer onto the coating material. Where desired, the development process can be completed using spin rinsing and / or drying. Suitable rinsing solutions include, for example, ultrapure water, methanol, ethanol, propanol, and combinations thereof in the case of negative patterning, and ultrapure water in the case of positive patterning. After the image is developed, the coated film is disposed on the substrate as a patterned coated film.

[0395] After the development step, the patterned coating film may be heat-treated to further condense, dehydrate, densify, or remove residual developer from the material. This heat treatment is particularly preferred for embodiments that introduce oxide coating materials into the final device, but it is sometimes also desirable to perform heat treatment on some embodiments where the coating film is ultimately removed as a resist, in order to further facilitate patterning and stabilize the coating film. In particular, baking the patterned coating film can be performed under conditions where the patterned coating film exhibits a desired level of etch selectivity. In some embodiments, the patterned coating film can be heated to a temperature of about 100°C to about 600°C; in further embodiments, it can be heated to a temperature of about 175°C to about 500°C; and in additional embodiments, it can be heated to a temperature of about 200°C to about 400°C. Heating can be performed for at least about 1 minute, in other embodiments for about 2 minutes to about 1 hour, and in further embodiments for about 2.5 minutes to about 25 minutes. Heating can be performed in air, in a vacuum, or in an atmosphere of inert gas such as Ar or N2. Those skilled in the art will understand that additional ranges of temperature and time for heat treatment within the aforementioned defined range are included within the scope of this disclosure. Similarly, non-thermal treatments, including full-surface UV exposure or exposure to oxidizing plasmas such as O2, can also be used for the same purpose.

[0396] For existing organic photoresists, if the aspect ratio (height divided by width) of the structure becomes very large, the structure is prone to pattern collapse. Pattern collapse may be related to the mechanical instability of high aspect ratio structures, where forces associated with the processing steps, such as surface tension, deform the structural elements. Low aspect ratio structures are more stable regarding potential deformation forces. By using the precursor in the dry process and the photoresist solution in the wet process described in this specification, structures with thinner coating films can be effectively processed, thus achieving improved patterning without the need for high aspect ratio patterned coating films. Therefore, for patterned coating films, very high-resolution features are formed without relying on high aspect ratio features.

[0397] The resulting structure can have sharp edges and very low linewidth roughness. In particular, in addition to reducing linewidth roughness, it also enables the formation of high contrast, small features and the space between features, and the ability to form extremely high-resolution two-dimensional patterns (e.g., sharp corners). Therefore, in some embodiments, adjacent straight portions of adjacent structures can have an average pitch (half-pitch) of about 60 nm (30 nm half-pitch), in some embodiments it can have an average pitch (half-pitch) of about 50 nm (25 nm half-pitch), and in a further embodiment it can have an average pitch (half-pitch) of about 34 nm (17 nm half-pitch).

[0398] The spacing is evaluated by design and can be confirmed by scanning electron microscopy (SEM), for example, by top-view images. In the context of this specification, spacing refers to the spatial period of repeating structural elements, i.e., the distance between centers; as is commonly used in this art, half-spacing is half the spacing. The feature size of the pattern can also represent the average width of features generally evaluated away from corners, etc. Additionally, features can also refer to gaps between material elements and / or material elements themselves. In some embodiments, the average width can be about 25 nm or less, in further embodiments about 20 nm or less, and in additional embodiments about 15 nm or less. The average linewidth roughness can be about 5 nm or less, in some embodiments about 4.5 nm or less, and in further embodiments about 2.5 to about 4 nm. The evaluation of linewidth roughness is performed by deriving a 3σ deviation relative to the average linewidth using analysis of top-view SEM images. The average includes both high-frequency and low-frequency roughness, i.e., short correlation length and long correlation length, respectively. The linewidth roughness of organic resists is mainly characterized by a long correlation length, but the organometallic coating material of this embodiment exhibits a significantly short correlation length. In pattern transfer processes, short, correlated roughness is smoothed between etching processes, enabling the generation of patterns with significantly improved fidelity. Those skilled in the art will understand that additional ranges of spacing, average width, and linewidth roughness within the aforementioned defined ranges are included within the scope of this disclosure.

[0399] Further processing of patterned coated films

[0400] After a patterned coating film is formed on the substrate, the substrate can be further processed to facilitate the formation of the selected device. Furthermore, to complete the structure, further material attachment, etching, and / or patterning can typically be performed.

[0401] The patterned coating film may or may not be removed. In either case, the quality of the patterned coating film is expected to be improved in order to form improved devices (e.g., devices with smaller setup areas).

[0402] Alternatively or additionally, the attachment of further material according to the mask pattern can alter the properties of the underlying structure and / or provide contact with the underlying structure. The further coating material can be selected based on desired material properties. Furthermore, since the density of the patterned inorganic coating material provides high implantation resistance, ions can be selectively implanted into the underlying structure through the openings in the mask. In some embodiments, the further attached material can be a dielectric, semiconductor, conductor, or other suitable material. The further attached material can be attached using suitable means, such as solution-based steps, chemical vapor deposition (CVD), sputtering, physical vapor deposition (PVD), or other suitable means.

[0403] Typically, multiple additional layers can be attached. Additional patterning can be performed in conjunction with the attachment of two or more layers. Where desired, optional additional patterning can be performed using additional amounts of the coating material described in this specification, polymer-based resists, other patterning methods, or combinations thereof.

[0404] As mentioned above, the patterned coating film may or may not be removed.

[0405] The patterned coating film is assembled into the structure without being removed. In the embodiment where the patterned coating film is assembled into the structure, the characteristics of the patterned coating film can be selected in a way that provides not only the desired patterning characteristics but also the characteristics of the material within the structure.

[0406] When it is desired to remove a patterned coating, the patterned coating functions as a resist, as previously intended. The patterned coating serves to pattern subsequently applied material and / or selectively etch the substrate via spaces within the condensed coating material before removal. The condensed coating material can be removed using a suitable etching process. Specifically, to remove the condensed coating material, dry etching can be performed, for example, using BCl3 plasma, Cl2 plasma, HBr plasma, Ar plasma, or plasma based on other suitable process gases. Alternatively or additionally, to remove the patterned coating material, wet etching can be performed, for example, using aqueous solutions of acids or alkalis, HF (water), or buffered HF (water) / NH4F, or oxalic acid, etc.

[0407] This photoresist material can be used for multiple patterning. That is, this process can be applied to processes involving multiple coatings and multiple patterning. Regarding multiple patterning, a significant difference between the inorganic coating material described in this specification and existing organic photoresists is that organic photoresists remain soluble in existing photoresist casting solvents even after heating and baking. The photoresist material described in this specification can be cured by heating and baking, resulting in its insolubility in organic solvents, thus allowing the formation of coating layers, etc., on the photoresist material.

[0408] Example

[0409] The following examples illustrate the present invention in more detail, but the present invention is not limited to these examples as long as it does not depart from its spirit. It should be noted that, unless otherwise specified, "parts" and "%" in the examples refer to a mass standard.

[0410] Unless otherwise specified, the following raw materials shall be used as raw materials.

[0411] In addition, tin compounds are sometimes referred to as follows.

[0412] [Precursor]

[0413] ·iPrSn(NMe2)3: Isopropyltris(dimethylamide)tin, 119 Sn-NMR: -64ppm...Compound(1)

[0414] [Tin compounds as impurities (A2, A3, A4)]

[0415] Tin compound (A2): iPr2Sn(NMe2)2: diisopropyl, 119 Sn-NMR: -18ppm···Compound(2)

[0416] Tin compound (A3): Sn(NMe2)4: tetraamide, 119 Sn-NMR: -120ppm...Compound(3)

[0417] Tin compounds (A4): iPrSn(NMe2)2(NMeCHNMe2), 119 Sn-NMR: -82ppm...Compound(4)

[0418] Tin compounds other than compounds (1) to (4): other impurities

[0419] [Organic solvents]

[0420] • Dehydrated hexane: n-Hexane (dehydrated) (manufactured by Kanto Chemical Co., Ltd.) (moisture content 10 ppm)

[0421] <<Preparation and Analysis of Monoalkyltin Compounds (Precursors)>>

[0422] The prepared precursor was prepared in a manner that constitutes the composition of the comparative examples / exemplary embodiments described below. The composition of each functional group, etc., in the obtained precursor is detailed in Tables 2 and 3 below.

[0423] It should be noted that the abbreviations for the organic groups R in Tables 2 and 3 are as follows.

[0424] iPr: Isopropyl, molecular formula C3H7

[0425] ·tBu: tert-butyl, molecular formula C4H9

[0426] ·1Me-cPen: 1-Methylcyclopentyl, molecular formula C6H 11

[0427] ·3Butenyl: 3-Butenyl, molecular formula C4H7

[0428] <Comparative Example 1-1>

[0429] Precursor L1: Monoalkyl tin compounds (precursors) with a purity of less than 99.2 mol% (R = isopropyl) of RSn(NMe2)3 were prepared and the compositions (contents of tin compounds (1) to (4)) shown in Table 1 and the article were prepared.

[0430] [Table 1]

[0431] (Manufacturing method of precursor L1)

[0432] Prepare and use a 200L glass reactor (with a jacket for circulating water) that is shielded from light, a cooling condenser with an internal coil, a stirring device (stirring blades: double star type, diameter: 350mm, width: 110mm, made of SUS coated with Teflon (registered trademark)), and a 50L glass dripping device.

[0433] After reducing the pressure in the reaction apparatus to 3 kPa, three nitrogen purging operations were performed. Hexane (36.6 kg, water 21 ppm) and n-butyllithium [41.0 kg, 96.8 mol (3.09 eq), 15% hexane solution (containing the equivalent of 34.9 kg of hexane)] were added, and the mixture was stirred at 150 rpm [blade tip speed (m / s) = 3.14 × 0.35 × 150 / 60 = 2.74 (m / s)] while maintaining the temperature between -5 and 10°C. Dimethylamine (8.69 kg, 193.6 mol, 6.18 eq) was added dropwise over 1 hour. The resulting lithium dimethylamino slurry was stirred at 23–27°C for 1 hour.

[0434] The temperature of the obtained lithium dimethylamino slurry was adjusted to -10°C, and while maintaining the temperature range (internal temperature -10°C to 0°C) of the hexane solution containing isopropyltrichlorotin (8.40 kg, 31.3 mol, 1.00 eq) (4.20 kg based on the amount of hexane), it was added dropwise over 2 hours from a glass dropping apparatus. Then, the dropping apparatus was rinsed with hexane (0.61 kg) while the dropping apparatus was added dropwise.

[0435] After dropwise addition, the temperature was raised to 25°C over 3 hours and stirred for 16 hours. The resulting reaction solution was filtered through a pressure filter to remove the white solid (LiCl), yielding a clear filtrate. The white solid was further washed with dehydrated hexane (7.3 kg × 3), and the filtrates were combined. The resulting reaction solution was concentrated under reduced pressure. The concentrated solution (10.3 kg) was directly packed into a light-shielded glass simple distillation apparatus under a nitrogen atmosphere. The apparatus was introduced into the distillation apparatus under a nitrogen inert gas atmosphere and simple distillation was performed under reduced pressure and heating to obtain the corresponding tin compound (1) as a fraction (distillation apparatus: glass simple distillation apparatus wrapped with light-shielding cloth; distillation conditions: internal temperature: 70–80°C; reduced pressure: 0.3 kPa). The tin compound (1) obtained by simple distillation was purified by precision distillation using a distillation column with 30 theoretical plates and a reflux ratio of 10. The precision distillate of the obtained tin compound (1) was used as precursor L1.

[0436] <Comparative Examples 1-2>

[0437] Precursor L2: RSn(NMe2)3, purity 99.8 mol% (R = tert-butyl)

[0438] <Comparative Examples 1-3>

[0439] Precursor L3: RSn(NMe2)3, purity 99.9 mol% (R = 1-methylcyclopentyl)

[0440] <Comparative Examples 1-4>

[0441] Precursor L4: RSn(OtBu)3, purity 99.7 mol% (R = 3-butenyl)

[0442] <Example 1-1>

[0443] Precursor L5: A substance formed by mixing the above precursors L1 and L2 in a mass ratio of 7:3.

[0444] <Examples 1-2>

[0445] Precursor L6: A substance formed by mixing the above precursors L1 and L3 in a mass ratio of 7:3.

[0446] <Examples 1-3>

[0447] Precursor L7: A substance formed by mixing the above precursors L1 and L4 in a mass ratio of 7:3.

[0448] [Table 2]

[0449] <<Preparation and Analysis of Tin Hydrolysates Based on Hydrolysis>>

[0450] <Comparative Example 2-1>

[0451] As the apparatus for mixing and hydrolysis, a 100 mL three-necked glass flask (shielded with aluminum foil and dried after rinsing with ultrapure water) was used, along with a magnetic stirrer (stirring bar: 20 mm long Teflon rod). Under a non-reactive gas atmosphere (G1 grade nitrogen, manufactured by Taiyo Nippon Sanso), and under light-shielding conditions, 10 mL of dehydrated hexane (10 ppm water content) was added to the flask using a gas-tight syringe. Then, 1.0 g (3.4 mmol, calculated as iPrSn(NMe2)3) of precursor L1 was added to the flask using the gas-tight syringe. The resulting liquid was cooled in an ice bath, and while stirring at 200 rpm, 1.0 mL of dehydrated water (18.2 MΩ) was added over 3 minutes while maintaining a temperature of 0–10°C. This resulted in a white solid slurry. This slurry was further stirred for 10 minutes while maintaining a temperature of 0–10°C. The slurry was then filtered through filter paper (Kiriyama 5B) to obtain a white solid. The solid was washed twice with deionized water (18.2 MΩ) (3.0 mL) and collected in a 20 mL glass bottle. The glass bottle was vacuum dried at 40 °C for 8 h to obtain the white solid tin hydrolysate H1.

[0452] The composition and crystallinity of the obtained tin hydrolysate were analyzed using the following measuring apparatus and conditions, and the results are shown in Table 3 below.

[0453] [NMR Analysis Apparatus and Methods]

[0454] • NMR analysis apparatus: Bruker, Avance Neo, 600MHz; probe: Cryo 5mm BBO

[0455] The tin hydrolysate was dissolved in the assay solvent shown in the examples described later, and the NMR was measured. 1 H-NMR, 13 C-NMR, 119 Sn-NMR and their related NMR spectra). Based on the obtained NMR spectra, and using the composition and purity analysis items of the tin hydrolysate mentioned above, the composition and purity analysis of the tin hydrolysate were performed.

[0456] [ESI-MS Analysis Apparatus and Methods]

[0457] • ESI-MS analyzer: Waters Corporation, Xevo G2-XS Qtof, Measurement mode: ESI positive ion mode, Solvent: Acetonitrile

[0458] Analytical method: The theoretical mass spectrum, which includes the isotopes of each tin compound, is calculated using the analysis software attached to the device. The peak with the highest intensity is detected from the theoretical mass spectrum as the peak of each tin compound, and the intensity of the peak is quantified.

[0459] [XRD Analysis Apparatus and Methods]

[0460] • XRD analysis apparatus: PANalytical, X'Pert Pro MPD; X-ray source: CuKα lumped optical system; scanning range: 3–50°; half-width analysis method: calculated using profile fitting (Pearson-VII function, pseudo-Voigt function).

[0461] <Comparative Examples 2-2 to 2-4>

[0462] In Comparative Example 2-1, the precursors were changed to precursors L2 to L4 as shown in Table 3 below. Otherwise, the same operation as in Comparative Example 2-1 was performed (the amount of precursors was uniformly 1.0 g, and the same amount of reagents were used) to obtain tin hydrolysates H2 to 4 as shown below. The composition and crystallinity of the obtained tin hydrolysates were analyzed and are shown in Table 3 below.

[0463] <Example 2-1>

[0464] As the apparatus for mixing and hydrolysis, a 100 mL three-necked glass flask (shielded with aluminum foil and dried after washing with ultrapure water) was used, along with a magnetic stirrer (stirrer: Teflon rod, 20 mm in length). Under an inert gas atmosphere (G1 grade nitrogen, manufactured by Taiyo Nippon Sanso), and under light-shielding conditions, 10 mL of dehydrated hexane (10 ppm water content) was added to the flask using a gas-tight syringe. Then, under an inert gas atmosphere and under light-shielding conditions, 0.70 g (2.38 mmol) of precursor L1 and 0.30 g (0.97 mmol) of precursor L2 were added using a gas-tight syringe. The resulting liquid was cooled in an ice bath and stirred at 200 rpm for 5 minutes. This prepared a mixture of precursors L1 and L2 (molar ratio of precursors L1:L2 = 0.71:0.29). For this mixture, deionized water (18.2 MΩ) (1.0 mL) was added over 3 minutes while maintaining the temperature at 0–10°C. This resulted in a slurry of white solid. This slurry was further stirred for 10 minutes while maintaining the temperature at 0–10°C. The slurry was then filtered through filter paper (Kiriyama 5B) to obtain a white solid. The solid was washed twice with deionized water (18.2 MΩ) (3.0 mL) and collected in a 20 mL glass bottle. The glass bottle was vacuum dried at 40°C for 8 hours to obtain a white solid tin hydrolysate H5.

[0465] <Example 2-2>

[0466] Using the same method as in Example 2-1, a mixture of precursors L1 and L2 was prepared using 0.70 g (2.38 mmol) of precursor L1 and 0.30 g (0.90 mmol) of precursor L2 (molar ratio of precursors L1:L2 = 0.73:0.27). In addition, tin hydrolysate H6 was obtained through the same procedure.

[0467] <Example 2-3>

[0468] Using the same method as in Example 2-1, a mixture of precursors L1 and L3 was prepared using 0.70 g (2.38 mmol) of precursor L1 and 0.30 g (0.90 mmol) of precursor L3 (molar ratio of precursors L1:L2 = 0.76:0.24). In addition, tin hydrolysate H7 was obtained through the same procedure.

[0469] [Table 3]

[0470] [Analysis results of tin hydrolysate H1]

[0471] (R = isopropyl chemical formula C3H7)

[0472] Tin hydrolysate H1119 The results of the Sn-NMR measurements are shown in Table 3. A 1:1 peak was observed in SnNMR (MeOD): 5-coordinate (RSnO4): -337 ppm and 6-coordinate (RSnO5): -513 ppm. This is consistent with the tin dodecomer cluster (nBuSn) reported in Organometallics 19, 2000, 1940-1949. 12 O 14 The NMR results for (OH)6 are correlated. That is, the result is equivalent to the composition RSnO. (3 / 2-x / 2) (OH) x Compounds.

[0473] The analytical results of H1, a tin hydrolysate, were obtained by electrospray ionization mass spectrometry (ESI-MS). Figure 1 The ESI-MS spectrum of H1 is shown below. In this spectrum, an ESI-MS spectrum corresponding to the composition RSnO is observed. (3 / 2-x / 2) The divalent ion (specifically, chemical formula [(C3H7Sn)). 12 O 14 (OH)6] +2 The peaks corresponding to the calculated value m / z = approximately 1134 and the monovalent ion (m / z = approximately 2268), as well as their potassium adducts (equivalent to m / z + 40). The divalent ion corresponds to the chemical formula (RSn). 12 O 14 (OH)6 +2 .

[0474] [Analysis results of tin hydrolysate H2]

[0475] (R = tert-butyl, chemical formula C4H9)

[0476] Tin hydrolysate H2 119 The results of the Sn-NMR measurements are shown in Table 3. A peak of approximately 0.9:1 was observed at the 5-coordinate:6-coordinate ratio, yielding a result equivalent to the composition RSnO. (3 / 2-x / 2) (OH) x Compounds.

[0477] The analytical results of H2, a tin hydrolysate, obtained by electrospray ionization mass spectrometry (ESI-MS) analysis, were obtained in... Figure 2 The ESI-MS spectrum of H2 is shown below. In this spectrum, an ESI-MS spectrum corresponding to the composition RSnO2 was observed. (3 / 2-x / 2) The divalent ion (specifically, chemical formula [(RSn)]) 12 O 14 (OH)6] +2 The peaks corresponding to the calculated value m / z = approximately 1218 and the monovalent ion (m / z = approximately 2435).

[0478] [Analysis results of tin hydrolysate H3]

[0479] (R = 1-methylcyclopentyl chemical formula C6H) 11 )

[0480] The NMR identification results of tin hydrolysate H3 are shown in Table 3. A peak of approximately 0.6:1 was observed at the 5-coordinate:6-coordinate ratio, yielding a composition equivalent to RSnO. (3 / 2-x / 2) (OH) x Compounds. 1 HNMR(600MHz MeOD / CDCl3 1 / 1): 2.0-2.4(m,2H),1.6-1.9(m,6H),1.48(Me,3H RSnO4),1.28(Me,3H RSnO5)

[0481] The analytical results of H3, a tin hydrolysate, obtained by electrospray ionization mass spectrometry (ESI-MS) analysis. Figure 3 The ESI-MS spectrum of H3 is shown below. In this spectrum, a compound equivalent to RSnO was observed. (3 / 2-x / 2) The compound is a divalent ion (specifically, with the chemical formula [R(Sn)]). 12 O 14 (OH)6] +2 The peaks corresponding to the calculated value m / z = approximately 1374 and the monovalent ion (m / z = approximately 2747).

[0482] [Analysis results of tin hydrolysate H4]

[0483] (R = 3-Butenyl, chemical formula C4H7)

[0484] The NMR identification results of tin hydrolysate H4 are shown in Table 3. A peak of approximately 0.4:1 was observed at the 5-coordinate:6-coordinate, yielding a result equivalent to RSnO. (3 / 2-x / 2) (OH) x Compounds.

[0485] The analytical results of H4, a tin hydrolysate, obtained by electrospray ionization mass spectrometry (ESI-MS) analysis. Figure 4 The ESI-MS spectrum of H4 is shown below. In this spectrum, a structure corresponding to the composition RSnO was observed. (3 / 2-x / 2) The compound is a divalent ion (specifically, with the chemical formula [(RSn)]). 12 O 14 (OH)6] +2 The peaks corresponding to the calculated value m / z = approximately 1240 and the monovalent ion (m / z = approximately 2480).

[0486] [Analytical results of tin hydrolysate H5]

[0487] (R A =Isopropyl chemical formula C3H7, R B =tert-butyl (chemical formula C4H9)

[0488] The NMR identification results of tin hydrolysate H5 are shown in Table 3. A peak of approximately 0.84:1 was observed at the 5-coordinate:6-coordinate ratio, yielding a composition equivalent to RSnO. (3 / 2-x / 2) (OH) x The compound. Furthermore, apart from k1 and k2, the corresponding peaks do not exist at detectable intensities, therefore the value of (k1+k2) / (k3), representing purity, is 0.99 or higher. Additionally, based on... 1 H-NMR, 13 The C-NMR analysis results were used to calculate the molar ratio R of the composition. A :R B The ratio is 70 / 30. This composition is related to the molar ratio of the mixed precursors used as raw materials. Figure 5A The NMR spectrum of H5 is shown in ~C.

[0489] The analytical results of H5, a tin hydrolysate, were obtained by electrospray ionization mass spectrometry (ESI-MS). Figure 5D The image shows the ESI-MS spectrum of H5. In this spectrum, [the image shows a spectrum equivalent to RSnO]. (3 / 2-x / 2) Compounds are divalent ions (specifically, chemical formula [(R A Sn)8(R B Sn)4O 14 (OH)6] +2 The peaks corresponding to the calculated value m / z = approximately 1162 and the monovalent ion (m / z = approximately 2336) appear with the highest intensity, which is equivalent to having 7 R A =Isopropyl, 5 R B =A tin compound with a tert-butyl substituent (P3AB). Additionally, equivalent to R was observed around it. A and R B The peaks of compounds with different compositions are observed. That is, it can be seen that within one molecule of tin hydrolysate, R exists as different types of alkyl groups. A and R B .

[0490] Table A-1 below shows the molecular weight, peak intensity, and content (%) of each tin compound detected by ESI-MS. Ten types of tin compounds (P3AB) were detected in this tin hydrolysate H5. Similarly, tin compounds (P3A) and (P3B) with a single organic group R were also detected. Furthermore, the content of each tin compound was calculated as described above using the following formula.

[0491] The content (%) of each tin compound (P3AB) = [peak intensity of each tin compound (P3AB)] / [sum of peak intensities of each tin compound (P3AB), (P3A), and (P3B)]

[0492] The total percentage of all tin compounds (P3AB) in this formula is 97.2%. Furthermore, the tin compound with the highest percentage content is the one containing seven R atoms in a single molecule. A =Isopropyl, 5 R B =Tertiary butyltin compounds, with an abundance of 16.2%. Furthermore, the most abundant tin compounds are those containing only a single organic group R. A The content of tin compound (P3A) exceeds 1.8%.

[0493] [Table A-1]

[0494] In addition, such as Figure 5E As shown, regarding the organic groups R of various tin compounds A A curve plotted with the number of compounds on the x-axis and the content (%) on the y-axis shows a single-peak distribution structure with the tin compound having the highest content (%) as the peak (maximum). Furthermore, based on the molecular weight and content (%) of each tin compound, as shown in Table A-2 below, the number-average molecular weight Mn, weight-average molecular weight Mw, and molecular weight distribution Mw / Mn of tin hydrolysate H5 were calculated.

[0495] [Table A-2]

[0496] [Analysis results of tin hydrolysate H6]

[0497] (R A =Isopropyl chemical formula C3H7, R B =1-Methylcyclopentyl chemical formula C6H 11 )

[0498] The NMR identification results of tin hydrolysate H6 are shown in Table 3. A peak of approximately 1.88:1 was observed at the 5-coordinate:6-coordinate, yielding a result equivalent to RSnO. (3 / 2-x / 2) (OH) x Compounds. Additionally, based on... 1 H-NMR, 13 The C-NMR analysis results were used to calculate the molar ratio R of the composition. A :R BThe value is 75 / 25. Furthermore, apart from k1 and k2, the corresponding peaks do not exist at detectable intensities, therefore the value of (k1+k2) / (k3), representing purity, is 0.99 or higher. This composition is related to the molar ratio of the mixed precursors used as raw materials. Figure 6A The NMR spectrum of H6 is shown in ~C.

[0499] The analytical results of H6, a tin hydrolysate, obtained by electrospray ionization mass spectrometry (ESI-MS) analysis. Figure 6D The image shows the ESI-MS spectrum of H6. In this spectrum, [the image shows a structure corresponding to the compositional formula RSnO]. (3 / 2-x / 2) divalent ions (specifically, chemical formula [(R) A Sn) 10 (R B Sn)2O 14 (OH)6] +2 The calculated values ​​m / z for divalent ions (m / z = approximately 1154) and monovalent ions (m / z = approximately 2306) correspond to peaks with the highest intensity, which is equivalent to having 11 R... A =Isopropyl, 1 R B =1-Methylcyclopentyl substituent tin compound (P3AB). Additionally, R equivalents were observed around it. A and R B The peaks of tin compounds with different compositions are observed. That is, it can be seen that within a single molecule of tin hydrolysate, R exists as different types of alkyl groups. A and R B .

[0500] Table B-1 below shows the molecular weight, peak intensity, and content (%) of each tin compound detected by ESI-MS. As shown in Table B-1, 11 types of tin compounds (P3AB) contained in this tin hydrolysate H6 were detected, and similarly, compounds with a single organic group R were also detected. A Tin compounds (P3A) were present, while (P3B) was not detected. Furthermore, the content of each tin compound was calculated as described above using the following formula.

[0501] The content (%) of each tin compound (P3AB) = [peak intensity of each tin compound (P3AB)] / [sum of peak intensities of tin compounds (P3AB), (P3A), and (PB)]

[0502] The total percentage of all tin compounds (P3AB) in this formula is 84.8%. Furthermore, the tin compound with the highest percentage content is the one containing 11 R atoms in one molecule. A =Isopropyl, 1 R B=1-Methylcyclopentyl tin compounds, with an abundance of 19.0%. Furthermore, the tin compound with the highest abundance was found in compounds containing only a single organic group (R). A The content of tin compound (P3A) exceeds 15.2%.

[0503] [Table B-1]

[0504] In addition, such as Figure 6E As shown, regarding the organic groups R of various tin compounds A A curve plotted with the number of compounds on the x-axis and the content (%) on the y-axis shows a single-peak distribution structure with the tin compound having the highest content (%) as the peak (maximum). Furthermore, based on the peak molecular weight (Mi) and content (%) (Ni) of each tin compound, as shown in Table B-2 below, the number-average molecular weight Mn, weight-average molecular weight Mw, and molecular weight distribution Mw / Mn of tin hydrolysate H6 were calculated.

[0505] [Table B-2]

[0506] [Analysis results of tin hydrolysate H7]

[0507] (R A =Isopropyl chemical formula C3H7, R B =3-Butenyl (chemical formula C4H7)

[0508] The NMR identification results of tin hydrolysate H7 are shown in Table 3. A peak of approximately 1.1:1 was observed at the 5-coordinate:6-coordinate ratio, yielding a composition equivalent to RSnO. (3 / 2-x / 2) (OH) x The compound. Furthermore, apart from k1 and k2, the corresponding peaks do not exist at detectable intensities, therefore the value of (k1+k2) / (k3), representing purity, is 0.99 or higher. Additionally, based on... 1 H-NMR, 13 The C-NMR analysis results were used to calculate the molar ratio R of the composition. A :R B It is 78 / 22.

[0509] This composition is related to the molar ratio of the mixed precursors used as raw materials. Figure 7A The NMR spectrum of H7 is shown in section B.

[0510] The analytical results of H7, a tin hydrolysate, were obtained by electrospray ionization mass spectrometry (ESI-MS). Figure 7C The image shows the ESI-MS spectrum of H7. In this spectrum, [the image shows a structure corresponding to the compositional formula RSnO]. (3 / 2-x / 2)divalent ions (specifically, chemical formula [(R) A Sn) 10 (R B Sn)2O 14 (OH)6] +2 The peaks corresponding to the calculated value m / z = approximately 1148 and the monovalent ion (m / z = approximately 2300) appear with the highest intensity, and peaks equivalent to R are observed around them. A and R B The peaks of compounds with different compositions are observed. That is, it can be seen that within one molecule of tin hydrolysate, R exists as different types of alkyl groups. A and R B .

[0511] <<Solubility, Filterability, and Storage Stability of Corrosion Resist Solutions>>

[0512] Using the obtained tin hydrolysate, a resist-based solvent solution (resist solution) was prepared by the following method. The obtained resist solution was subjected to dissolution tests, filtration tests, and storage stability tests, and evaluated according to the following evaluation criteria.

[0513] <Comparative Examples 3-1 to 3-4, Examples 3-1 to 3-3>

[0514] Specifically, each of the tin hydrolysates (0.100g) of H1 to H7 and 4-methyl-2-pentanol (4.90g) were weighed into 20mL transparent glass bottles to prepare a photoresist solution. The bottle containing the photoresist solution was placed in an ultrasonic generator containing water at room temperature (23°C) and ultrasonic waves were applied for 5 minutes to perform the dissolution operation.

[0515] <Comparative Examples 3-5>

[0516] Instead of the resist solution of Comparative Example 3-1, a resist solution further mixed with 4.0 g of the mixture obtained from H1 and 1.0 g of the mixture obtained from H2 was prepared according to Japanese Patent Application Publication No. 2019-500490. As with Comparative Example 3-1, ultrasonic waves were applied for 5 minutes to perform the dissolution operation again.

[0517] [Methods for evaluating solubility]

[0518] The solubility of tin hydrolysates is evaluated by comparing the turbidity (transparency) when the tin hydrolysates are dissolved in a resist solvent at a certain concentration. As a specific method, 5.0 g of a mixture containing 2.0% tin hydrolysates in 4-methyl-2-pentanol, as disclosed in Japanese Patent Application Publication No. 2019-500490, was prepared. The turbidity (transparency) of this liquid was compared with that of a standard turbidity solution, and the solubility of the corresponding tin hydrolysates was evaluated by visual inspection. As the standard turbidity solution, kaolin turbidity standard solutions (0 degrees (clear), 50 degrees, 100 degrees, 500 degrees, and 1000 degrees (white turbidity)) as shown in JIS K0110 were used, and the turbidity close to that of the standard turbidity solution was evaluated according to evaluation criteria 1 to 5 below.

[0519] (Evaluation Criteria)

[0520] • Turbidity rating 1: 0 degrees (transparent)

[0521] Turbidity rating 2: 50 degrees

[0522] Turbidity rating 3: 100 degrees

[0523] Turbidity rating 4: 500 degrees

[0524] • Turbidity rating 5: 1000 degrees (cloudy)

[0525] [Filtering Evaluation Methods]

[0526] The filterability of tin hydrolysate is evaluated by comparing the degree of filter clogging using the liquid obtained by dissolving tin hydrolysate in a resist solvent at a certain concentration.

[0527] As a specific method, 5.0 g of a mixture containing 2.0% tin hydrolysate in 4-methyl-2-pentanol, as disclosed in Japanese Patent Application Publication No. 2019-500490, was prepared, and the degree of clogging when filtering the liquid was evaluated according to the following evaluation criteria.

[0528] As a specific procedure, 5.0 g of the mixture was heated to a filter with a pore size of 0.2 μm (approximately 300 kPa) using a 10 mL syringe, and the mixture was then filtered, and the results were evaluated accordingly.

[0529] (Filter used: 0.2μm, PTFE, effective filtration area 4.0cm²) 2 Advantec manufactures disposable membrane filter units (DISMIC 25HP045AN).

[0530] (Evaluation Criteria)

[0531] • Set the setting to "1" for filtering 5.0g without clogging.

[0532] • Set the condition that can filter particles larger than 2.0g without causing clogging to be set to "2".

[0533] • Set to "3" for blockages below 2.0g.

[0534] [Methods for evaluating storage stability]

[0535] In the method for testing filtration, the resist solution, after being filtered, is introduced into a brown glass bottle (20 mL) into the atmosphere, and the bottle cap is closed. Under these conditions, it is stored at 20°C in the dark for one month. After this storage period, the resist solution is transferred to a transparent bottle and evaluated using the same method as for solubility evaluation; the results are used as an assessment of storage stability.

[0536] [Table 4]

[0537] According to Table 4 above, and from Examples 3-1 to 3-3, it can be seen that when using a mixture of two or more organic groups R (R A R B When the precursor of tin is used, the resulting tin hydrolysate has high solubility, and a resist solution with high storage stability can be obtained.

[0538] Furthermore, as can be seen from Comparative Examples 3-1 to 3-4, the use of a single organic group (R only) A The tin hydrolysate obtained from the precursor has high crystallinity, low solubility, and poor storage stability.

[0539] Furthermore, as can be seen from Comparative Examples 3-5, according to Japanese Patent Publication No. 2019-500490, even when mixed with two or more single organic groups (R only), A In the case of tin hydrolysates composed of α, β, and α, the solubility is also low. That is, if a tin compound does not have more than two alkyl groups in a single molecule, it is impossible to obtain a tin hydrolysate with high solubility.

[0540] <<The Production of Patterned Thin Films>>

[0541] <Example 4>

[0542] The tin hydrolysates H5 to H7 obtained in Examples 3-1 to 3-3 were dissolved in 4-methyl-2-pentanol (5 mL) at a concentration of 2.0% using ultrasound. The resulting solution was filtered using a 0.2 μm injection filter to obtain a resist solution containing transparent tin hydrolysates.

[0543] A silicon wafer (Si substrate, 100 mm diameter) with an oxide surface was ozone treated and used as a substrate for attaching a thin film (film) of resist. The surface of the Si substrate was treated with hexamethyldisilazane (HMDS) vapor before resist attachment. The resist solution was spin-coated onto the substrate at 2000 rpm and baked at 90°C for 2 minutes on a heated plate. The film thickness after coating and baking was measured to be approximately 22 nm using an ellipsometry. Ultraviolet light was used (light source: xenon excimer lamp (172 nm, 7.2 eV), manufactured by Ushio Electric Corporation, light source intensity: 0.7 mW / cm²). 2 The coated substrate is exposed to a pattern, which projects the pattern onto the substrate. Then, the substrate is immersed in 2-heptanone for 15 seconds and rinsed for another 15 seconds with the same developer to remove the negative image, i.e., the unexposed part of the film, forming an image with only the exposed part of the pattern remaining (patterned film).

[0544] Compared to the case using tin compounds in the comparative example, the above-described patterned thin film has high sensitivity and low LWR (roughness), making it an excellent photoresist material.

[0545] The above embodiments illustrate specific aspects of the present invention, but these embodiments are merely illustrative and not intended to be limiting. Various modifications that will be apparent to those skilled in the art are also within the scope of the present invention.

Claims

1. A tin compound having tin atoms, an organic group R, and oxygen ligands and / or hydroxyl ligands, wherein, One molecule of the tin compound contains two or more of the aforementioned organic groups R, and comprises a Sn-O-Sn structure. The organic group R has 1 to 30 carbon atoms.

2. The tin compound according to claim 1, wherein, The tin compound is composed of the formula RSnO (3 / 2-X / 2) (OH) X This means that, in the formula, 0 ≤ x ≤ 3.

3. The tin compound according to claim 1 or 2, wherein, The tin compound contains the chemical formula (RSn). 12 O 14 (OH)6 +2 Compounds that represent cations.

4. The tin compound according to any one of claims 1 to 3, wherein, The organic group R has 3 to 10 carbon atoms.

5. The tin compound according to any one of claims 1 to 4, wherein, The organic group R is a hydrocarbon group.

6. The tin compound according to any one of claims 1 to 5, wherein, The organic group R is a hydrocarbon group, and 20 mol% to 99 mol% of the substituents constituting the organic group R are secondary hydrocarbon groups R. 2 .

7. The tin compound according to any one of claims 1 to 5, wherein, The organic group R is a hydrocarbon group, and 1 mol% to 50 mol% of the substituents constituting the organic group R are tertiary hydrocarbon groups R. 3 .

8. The tin compound according to any one of claims 1 to 5, wherein, The organic group R is a hydrocarbon group, and 1 mol% to 50 mol% of the substituents constituting the organic group R are cyclic hydrocarbon groups R. c .

9. The tin compound according to any one of claims 1 to 5, wherein, The organic group R is a hydrocarbon group, and 1 mol% to 50 mol% of the substituents constituting the organic group R are hydrocarbon groups with unsaturated bonds. u .

10. The tin compound according to any one of claims 1 to 9, wherein, The organic group R comprises isopropyl and tert-butyl.

11. The tin compound according to any one of claims 1 to 10, wherein, The organic group R comprises isopropyl and methylcyclopentyl.

12. The tin compound according to any one of claims 1 to 11, wherein, The organic group R contains a saturated hydrocarbon group.

13. The tin compound according to any one of claims 1 to 12, wherein, The organic group R contains more than 50 mol% isopropyl.

14. A tin composition comprising the tin compound according to any one of claims 1, 3 to 13, wherein, When measured using ESI-mass, it contains three or more substances with the chemical formula (R) A Sn) x (R B Sn) y O 14 (OH)6 +2 The represented tin compound with cations (P3AB) Where x is an integer with 0 < x < 12, y is an integer with 0 < y < 12, and x + y = 12; in the proportion of the composition of the organic group R calculated by NMR measurement of the tin composition, the organic group with the largest proportion is taken as R A , and the organic group with the second largest proportion is taken as R B ; the organic group R may include organic groups other than the organic groups R A and R B .

15. The tin composition according to claim 14, wherein, The total content (%) of the tin compound (P3AB) calculated by the following formula A is 80% or more. <Calculation Formula A> The content (%) of the tin compound (P3AB) = [peak intensity of the tin compound (P3AB)] / [sum of peak intensities of all tin compounds (P3AB), (P3A), and (P3B)] The peak intensity refers to the peak intensity measured using ESI-MASS. The tin compound (P3A) indicates that it contains only a single organic group R. A Tin compounds, wherein the tin compound (P3B) represents a single organic group R. B Tin compounds.

16. The tin composition according to claim 15, wherein, The tin compound (P3AB-1) with the highest content (%) calculated by formula A has a content (%) exceeding that of the organic group R which contains only a single component. A The content of tin compound (P3A).

17. The tin composition according to any one of claims 14 to 16, wherein, Regarding the setting of the content (%) of each tin compound (P3AB), (P3A), and (P3B) in the tin composition as the y-axis, and the setting of the organic group R in one molecule as the y-axis... A The distribution shape of the curve plotted with the number of elements as the x-axis shows that, when the tin compound with the highest content is set as tin compound (P3AB-1), the tin compound (P3AB-1) has a peak (maximum point) and a single-peak distribution structure.

18. The tin composition according to any one of claims 14 to 17, wherein, The molecular weight distribution Mw / Mn, calculated from the peak molecular weight (Mi) and content (%) (Ni) of each tin compound (P3AB), (P3A), and (P3B) in the tin composition, has a value of 1.00001 to 1.

05.

19. The tin composition according to any one of claims 14 to 18, wherein, 119 The sum of the peak integrals (k1) of 5-coordinate Sn (-250ppm to -350ppm) and the sum of the peak integrals (k2) of 6-coordinate Sn (-450ppm to -600ppm) in Sn-NMR, relative to the sum of the peak integrals (k1+k2) of 6-coordinate Sn (-450ppm to -600ppm), is given by... 119 The ratio of the sum of all peak integral values ​​(including k1 and k2) in the range of 1000ppm to -1000ppm detected by Sn-NMR to (k3) [(k1+k2) / (k3)] is greater than 0.

9.

20. The tin composition according to any one of claims 14 to 19, wherein, 119 The ratio (k1 / k2) of the total integrated peak value (k1) of 5-coordinate Sn (-250ppm to -350ppm) to the total integrated peak value (k2) of 6-coordinate Sn (-450ppm to -600ppm) in Sn-NMR is 0.5 to 2.

5.

21. A method for manufacturing a tin compound and / or a tin composition, comprising a method for manufacturing a tin compound having tin atoms, an organic group R, and oxygen ligands and / or hydroxyl ligands, wherein, The process includes the following steps: <Step 1> Two or more precursors RSnX3(A1) with different structures of the organic group R are combined to obtain a precursor mixture, wherein X in A1 is a hydrolyzable group; <Step 2> Contact the precursor mixture with the organic solvent complex in liquid water.

22. The method for manufacturing the tin compound and / or tin composition according to claim 21, wherein, The process includes combining 100 parts by mass of the precursor mixture with 100 parts by mass or more of an organic solvent.

23. A tin compound or tin composition manufactured by the manufacturing method of claim 21 or 22.

24. A resist solution comprising a tin compound according to any one of claims 1 to 13 and / or a tin composition according to any one of claims 14 to 20, and an organic solvent.

25. A method for forming a pattern, comprising: The process of coating the resist solution of claim 24 onto the substrate; The process of exposing the object using radiation; And the process of developing using a developer.

26. A thin film on a substrate comprising any one of claims 1 to 13 and / or any one of claims 14 to 20.

27. A patterned thin film on a substrate, comprising a tin compound according to any one of claims 1 to 13 and / or a tin composition according to any one of claims 14 to 20.

28. A method for manufacturing a substrate, comprising the pattern forming method of claim 25.

Images