Azastannatran, stannatran, and methods for manufacturing and using the same

Abstract

Proper control of dialkyltin impurities in monoalkyltin compounds is required for the production of microelectronic products using EUV lithography. This invention provides compounds, methods for producing them, and uses that enable the deposition of high-purity tin-containing films. [Solution] Two classes of cyclic tin compounds, trioxaza-1-stannabicyclo-[3.3.3]-undecane, also known as stannatran, and tetraaza-1-stannabicyclo-[3.3.3]undecane, also known as azastannatran, are described, and methods for their preparation are also described. These cyclic tin compounds are resistant to rearrangement, and the formation of dialkyltin impurities is not observed during the synthesis, purification, or deposition of these compounds for forming oxostannate films.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority under U.S. Provisional Patent Application No. 63 / 294,089, filed on 28 December 2021, the disclosure of which is incorporated herein by reference in its entirety. [Background technology]

[0002] As semiconductor fabrication continues to advance, feature sizes (minimum design dimensions) continue to shrink, necessitating new processing methods. Certain organotin compounds have been shown to be useful for depositing tin oxide hydroxide coatings in applications such as extreme ultraviolet (EUV) lithography. For example, alkyltin compounds provide radiosensitive Sn-C bonds that can be used to pattern structures in lithography.

[0003] Materials used in microelectronics fabrication require extreme purity, with strict restrictions on organic contamination (e.g., reaction by-products), metal contamination, and particulate contamination. Purity requirements are generally strict, especially for lithography applications, as chemicals come into contact with semiconductor substrates and contain diisopropylbis(dimethylamino)stannane, a dialkyltin by-product, isopropyltris(dimethylamino)stannane (( i This is because organometallic impurities in compounds such as Pr)Sn(NMe2)3) can affect the properties of the resulting film. The precise purity target is determined by various factors, including performance metrics, but a typical minimum purity target is over 99.9%. Residual metals present in chemicals can deposit on semiconductor substrates and degrade the electrical performance of the fabricated devices. Typical metal specifications are less than 10 ppb for individual metals, and the total metal content does not exceed approximately 100 ppb.

[0004] The processing and performance of semiconductor materials can also be sensitive to dialkyltin impurities. Oxostanate cluster films have lower density when they contain dialkyl groups, and dialkyltin impurities such as R2SnX2, e.g., R2SnCl2, R2Sn(NMe2)2, are often the cause of gas release after gas-phase deposition or spin-on coating processes. Dialkyltin compounds are often trace components in monoalkyltin compounds as byproducts of synthesis, redistribution during storage, or formation during deposition. Proper control of dialkyltin impurities is required for the production of microelectronic products using EUV lithography. The high purity required by monoalkyltin precursor manufacturing processes is a challenge. Azastannatran and stannatran are attractive because their chemical structures resist redistribution reactions that lead to the formation of dialkyltin derivatives, enabling the deposition of high-purity tin-containing films. [Overview of the project] [Means for solving the problem]

[0005] In one embodiment, an aspect of the present disclosure is formula (I): [ka] The present invention relates to stannatrane having the following formula: (wherein R1 is a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to about 20 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to about 10 carbon atoms, and each R2 is independently hydrogen or a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms, provided that at least one R2 is not hydrogen).

[0006] In a second embodiment, the aspect of the present disclosure is formula (II): [ka] (wherein, R1 is a substituted or unsubstituted, linear or branched alkyl group having 1 to about 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to about 20 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to about 10 carbon atoms; each R2 is independently hydrogen or a substituted or unsubstituted, linear or branched alkyl group having 1 to about 10 carbon atoms; each R3 is independently hydrogen or a substituted or unsubstituted, linear or branched alkyl group having 1 to about 10 carbon atoms, provided that at least one R3 is not hydrogen relates to an azastannatrane having the following).

[0007] In summary, the following embodiments are proposed as particularly preferred within the scope of the present invention.

[0008] Embodiment 1: A stannatrane having the formula (I):

Chemical formula

[0009] Embodiment 2: The stannatrane according to Embodiment 1, having 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane:

Chemical formula

[0010] Embodiment 3: Formula 1-(3,3,3-trifluoropropyl)-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane: [ka] A stannarn according to Embodiment 1, having the following characteristics.

[0011] Embodiment 4: Formula 1-isopropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane: [ka] A stannarn according to Embodiment 1, having the following characteristics.

[0012] Embodiment 5: Stannatran according to any one of Embodiments 1 to 4, having a purity of at least about 99.9%.

[0013] Embodiment 6: Stannatran according to any one of Embodiments 1 to 5, containing less than approximately 0.1% of a dialkyltin compound.

[0014] Embodiment 7: A method for forming stannatran according to any one of Embodiments 1 to 6, A method comprising the step of reacting an alkali metal alkoxide with triisopropanolamine and an alkyltin trichloride compound having the formula R1SnCl3.

[0015] Embodiment 8: A method for forming stannatran according to any one of Embodiments 1 to 6, A method comprising the step of reacting an alkyltris(dimethylamino)tin compound having the formula R1Sn(NMe2)3 with triisopropanolamine.

[0016] Embodiment 9: Formula (II): [ka] (wherein R1 is a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to about 20 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to about 10 carbon atoms; each R2 is independently hydrogen or a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms; each R3 is independently hydrogen or a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms, provided that at least one R3 is hydrogen) Azastan Natran has (conditional on not being).

[0017] Embodiment 10: Azastannatran according to Embodiment 9, having a purity of at least about 99.9%.

[0018] Embodiment 11: Azastannatran according to Embodiment 9 or 10, containing less than approximately 0.1% of a dialkyltin compound.

[0019] Embodiment 12: A method for forming azastannatran according to any of Embodiments 9 to 11, A method comprising the step of reacting an alkyltris(dimethylamino)tin compound having the formula R1Sn(NMe2)3 with tris(2-aminoethyl)amine.

[0020] Embodiment 13: A method for forming an oxostanate film, The process of preparing the circuit board, A step of coating the substrate with a stannatran solution according to any of Embodiments 1 to 6, A step of drying and / or heating the coated substrate, The process of irradiating the coated substrate, The process involves exposing the irradiated substrate to oxygen or moisture to form an oxostanate film on the substrate. Methods that include...

[0021] Embodiment 14: A method for forming an oxostanate film, The process of preparing the circuit board, A step of coating the substrate with a solution of azastannatran described in any of embodiments 9 to 11, A step of drying and / or heating the coated substrate, The process of irradiating the coated substrate, A step of exposing the irradiated substrate to oxygen or moisture to form an oxostanate film on the substrate. Methods that include...

[0022] Embodiment 15: A method for forming an oxostanate film, A step of vaporizing stannatran according to any one of Embodiments 1 to 6 or preparing an aerosol thereof, The process of preparing the circuit board, A step of physically or chemically adsorbing vaporized or aerosolized stannatran onto a substrate, A process to form an oxostanate film on a substrate by physically or chemically adsorbing stannatran and subjecting it to a series of hydrolysis and irradiation steps, followed by oxidation or a second hydrolytic exposure. Methods that include...

[0023] Embodiment 16: A method for forming an oxostanate film, A step of vaporizing azastannatran according to any one of Embodiments 9 to 11 or preparing an aerosol thereof, The process of preparing the circuit board, A step of physically or chemically adsorbing vaporized or aerosolized azastannatran onto a substrate, A process to form an oxostanate film on a substrate by physically or chemically adsorbing azastannatran and subjecting it to a series of hydrolysis and irradiation steps, followed by oxidation or a second hydrolytic exposure. Methods that include...

[0024] Embodiment 17: A method for forming a patterned (patterned) film, comprising the steps of preparing the oxostanate film described in Embodiment 13, and exposing the film to discontinuous radiation by rasterizing with an electron beam or laser or by lithography masking.

[0025] Embodiment 18: A method for forming a patterned film, comprising the steps of preparing an oxostanate film as described in Embodiment 14, and exposing the film to discontinuous radiation by rasterizing with an electron beam or laser or by lithography masking.

[0026] Embodiment 19: A method for forming a patterned film, comprising the steps of preparing an oxostanate film as described in Embodiment 15, and exposing the film to discontinuous radiation by rasterizing with an electron beam or laser or by lithography masking.

[0027] Embodiment 20: A method for forming a patterned film, comprising the steps of preparing an oxostanate film as described in Embodiment 16, and exposing the film to discontinuous radiation by rasterizing with an electron beam or laser or by lithography masking.

[0028] Embodiment 21: A method for forming a continuous film, comprising the steps of preparing an oxostanate film as described in Embodiment 13, and exposing the film to blanket exposure using a suitable lithography mask to obtain an optically transparent tin oxide conductive film.

[0029] Embodiment 22: A method for forming a continuous film, comprising the steps of preparing an oxostanate film as described in Embodiment 14, and exposing the film to blanket exposure using a suitable lithography mask to obtain an optically transparent tin oxide conductive film.

[0030] Embodiment 23: A method for forming a continuous film, comprising the steps of preparing an oxostanate film as described in Embodiment 15, and exposing the film to blanket exposure using a suitable lithography mask to obtain an optically transparent tin oxide conductive film.

[0031] Embodiment 24: A method for forming a continuous film, comprising the steps of preparing an oxostanate film as described in Embodiment 16, and exposing the film to blanket exposure using a suitable lithography mask to obtain an optically transparent tin oxide conductive film.

[0032] The following detailed description of preferred embodiments of the present invention will be better understood in conjunction with the accompanying drawings. For the purpose of illustrating the present invention, the drawings show currently preferred embodiments. However, it should be understood that the present invention is not limited to the exact arrangements and means shown. [Brief explanation of the drawing]

[0033] [Figure 1a] Figure 1a shows the XPS spectrum of a silicon wafer coated with 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane according to one embodiment of the present disclosure. [Figure 1b] Figure 1b shows the XPS spectrum of a silicon wafer coated with 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane according to another embodiment of the present disclosure. [Figure 2a] Figure 2a shows the XPS spectrum of a silicon wafer coated with 1-iso-propyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane according to one embodiment of the present disclosure. [Figure 2b]Figure 2b shows the XPS spectrum of a silicon wafer coated with 1-iso-propyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane according to another embodiment of the present disclosure. [Figure 3a] Figure 3a shows the XPS spectrum of a silicon wafer coated with 1-(3,3,3-trifluoropropyl)-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane according to one embodiment of the present disclosure. [Figure 3b] Figure 3b shows the XPS spectrum of a silicon wafer coated with 1-(3,3,3-trifluoropropyl)-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane according to another embodiment of the present disclosure. [Modes for carrying out the invention]

[0034] Aspects of this disclosure relate to a method for preparing soluble, high-purity cyclic tin compounds, which can be used to prepare high-density tin oxide nanostructured materials by first forming an organotin film, and subsequently optionally converting it to an inorganic thin film by heating and / or exposure to UV, EUV, or electron beam radiation. The resulting films have high optical density and reduced volatile byproducts associated with dialkyltin species that are inherent to other tin precursors or formed as byproducts during the deposition process. Volatile byproducts of concern excluded herein volatilize during processing but adsorb onto the surfaces of chambers, exposures, and process-related equipment, causing downtime and / or loss of feature definition. The generation of these impurities is associated with the Kocheshkov rearrangement of alkyltin compounds.

[0035] More specifically, this disclosure relates to two classes of cyclic tin compounds, trioxaza-1-stannabicyclo-[3.3.3]-undecane, more simply referred to as stannatran, and tetraaza-1-stannabicyclo-[3.3.3]undecane, more simply referred to as azastannatran. These cyclic tin compounds are resistant to the Kocheshkov rearrangement, and the formation of dialkyltin impurities is not observed during the synthesis, purification, or deposition of these compounds for the formation of oxostanate films. These cyclic tin compounds are stable at room temperature but can react with solid substrates as vapor or aerosol, or can be deposited onto substrates from solution. Upon subsequent exposure to UV irradiation (particularly to extreme UV radiation), these compounds lose their organic substituents to form shrinkage-resistant oxostanate films. The film can be patterned (patterned) by controlled exposure using electron beam or laser rasterization, or by full-surface conversion using a suitable lithography mask, resulting in an optically transparent tin oxide conductive film. In the structural formulas shown throughout this disclosure, the bonds between tertiary nitrogen atoms are usually considered to be coordinate bonds, but may be shown as either coordinate or covalent bonds.

[0036] Stannatran and Azastannatran Stannatran according to the embodiments of this disclosure is given by general formula (I): [ka] It holds.

[0037] In formula (I), R1 is a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to about 20 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to about 10 carbon atoms, and preferred R1 groups include methyl, ethyl, n-propyl, isopropyl, and n-butyl. Each R2 is independently hydrogen or a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms, wherein at least one R2 is not hydrogen. Preferably Each R2 is an alkyl group, most preferably a methyl group. If R1 and / or R2 are substituted, they may be substituted with one or more halogen atoms (such as chloro, bromo, fluoro, or iodine, including partial or complete halogenation) or a trimethylsilyl group.

[0038] Exemplary stannatrans include 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane, 1-(3,3,3-trifluoropropyl)-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane, and 1-isopropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane. [ka]

[0039] Azastannatran according to the embodiments of this disclosure is given by general formula (II): [ka] It holds.

[0040] In formula (II), R1 is a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to about 20 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to about 10 carbon atoms, wherein preferred R1 groups include methyl, ethyl, n-propyl, isopropyl, and n-butyl. Each R2 is independently hydrogen or a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms. Each R3 is independently hydrogen or a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms, wherein at least one R3 is not hydrogen. Preferably, each R2 and R3 is an alkyl group, most preferably a methyl group. If R1 and / or R2 and / or R3 are substituted, they may be substituted with one or more halogen atoms (including partially or completely halogenated, such as chloro, bromo, fluoro, or iodine) or a trimethylsilyl group.

[0041] Exemplary azastannatran is 1-isopropyl-2,5,8,9- shown below It is tetraaza-1-stannabicyclo[3.3.3]undecane. [ka]

[0042] In preferred compounds having formulas (I) and (II), the CH2CH2 groups bridging the oxygen and nitrogen atoms are substituted; that is, R2 in formula (I) and R3 in formula (II) are alkyl groups, preferably methyl. These compounds are preferred because they have lower melting points and higher solubility than their unsubstituted analogs. For effectiveness in EUV or other deposition processes, the most preferred R1 substituent is an alkyl group having two or more carbon atoms, such as ethyl, isopropyl, or n-butyl.

[0043] Stannatran and azastannatran according to embodiments of this disclosure exhibit thermal and storage stability both neat and in solution. Specifically, no decomposition was observed in solutions of the compounds described herein after 8 hours of UV light exposure or 1 week of heating at 35°C. Furthermore, if stannatran or azastannatran is synthesized as a mixture of cis and trans isomers (which can be separated and characterized), such isomer mixtures are also stable.

[0044] The stannatran and azastannatran described herein are, for example, 119 They have high purity, measured by known analytical methods such as Sn NMR, exceeding 98%, 99%, 99.5%, 99.7%, 99.8%, 99.9%, or even higher. Specifically, stannatran and azastannatran contain low levels (e.g., less than 2%, less than 1%, less than 0.5%, less than 0.3%, less than 0.2%, less than 0.1%, or lower) of dialkyltin impurities, such as particularly dialkylbis(dimethylamino)stannane. For the purpose of purity analysis, diastereomers of the compounds described herein may be considered the same compound.

[0045] method According to aspects of this disclosure, a method for producing stannatran having formula (I) comprises the alkoxylation of an alkyltin halide. Specifically, one method according to this disclosure comprises the step of reacting an alkali metal alkoxide with triisopropanolamine and an alkyltin trichloride having formula R1SnCl3. Suitable reaction conditions can be determined by routine experiments involving specific solvents that may be protic or aprotic. In a preferred embodiment, the method comprises the step of combining triisopropanolamine (preferably in a solvent such as methanol) with an excess alkali metal alkoxide such as sodium methoxide in a solvent such as methanol or triethylamine. Subsequently, the alkyltin trichloride (or other alkyltin halide) is added to the reaction mixture in a solvent (such as toluene) such that the alkyltin trichloride is added in a 1:1 molar ratio to triisopropanolamine. The reaction temperature is controlled to less than about 60°C, preferably about 20°C to about 60°C. After the completion of the reaction ( 119 The product (which can be monitored by Sn NMR) is purified by known methods such as fractional distillation.

[0046] The second method includes the step of reacting an alkyltris(dimethylamino)tin compound having the formula R1Sn(NMe2)3 with triisopropanolamine. Suitable reaction conditions can be determined by routine experiments involving specific solvents, preferably a protic solvent such as hexane or toluene, or an aprotic solvent such as THF. In a preferred embodiment, the method includes the step of combining the alkyltris(dimethylamino)tin compound with triisopropanolamine (preferably in a solvent such as toluene) so that the alkyltris(dimethylamino)tin compound and triisopropanolamine combine in a 1:1 molar ratio. The reaction temperature is controlled to less than about 60°C, preferably about 20°C to about 60°C. After the completion of the reaction ( 119 The product (which can be monitored by Sn NMR) is purified by known methods such as fractional distillation.

[0047] According to another aspect of this disclosure, a method for producing azastannatran having formula (II) involves the amino group transfer of an organostanylamine. Specifically, azastannatran having formula (II) can be prepared by reacting an alkyltris(dimethylamino)tin compound having formula R1Sn(NMe2)3 with tris(2-aminoethyl)amine. Suitable reaction conditions can be determined by routine experiments involving a specific solvent, preferably a protic solvent such as hexane or toluene, or an aprotic solvent such as THF. In a preferred embodiment, the method includes the step of combining the alkyltris(dimethylamino)tin compound with tris(2-aminoethyl)amine (preferably in a solvent such as toluene) such that the alkyltris(dimethylamino)tin compound and tris(2-aminoethyl)amine combine in a 1:1 molar ratio. The reaction temperature is controlled to less than about 60°C, preferably about 20°C to about 60°C. After the completion of the reaction ( 119 The product (which can be monitored by Sn NMR) is purified by known methods such as fractional distillation.

[0048] film Oxostanate films prepared from the stannatran and azastannatran compounds described herein are resistant to shrinkage during conversion to patterned structures or exhibit reduced stress cracking of continuous films. They can also form films with more than 80% light transmission in the visible wavelength region and sufficient electrical conductivity to form electrodes.

[0049] The oxostanate films described herein may instead be referred to as SnO:H films. The films may be patterned by controlled exposure by rasterizing with an electron beam or laser, or by full-surface conversion using a suitable lithography mask, resulting in optically transparent fluorine-doped tin oxide conductive films.

[0050] A method for forming an oxostanate film according to an aspect of the present disclosure includes the steps of: vaporizing a stannatran compound having formula (I) or an azastannatran compound having formula (II) or preparing an aerosol thereof; preparing a substrate; physically or chemically adsorbing the vaporized or aerosolized stannatran or azastannatran onto the substrate; and subjecting the physically or chemically adsorbed stannatran or azastannatran to a series of hydrolysis and irradiation steps, followed by oxidation or a second hydrolytic exposure, to form an oxostanate film on the substrate. The resulting film has high purity and is free from dialkyltin compound contamination. Each of these steps is described in detail below.

[0051] In the first method step, stannatran or azastannatran is vaporized or aerosolized by being incorporated into a carrier gas such as nitrogen or argon, or by volatilization in a vacuum at a suitable temperature, and then transported to a substrate. Suitable are any type of substrate known in the art on which it is desirable to form a film, such as a substrate containing one or more metal layers, insulating materials, semiconductor materials, or combinations thereof, including, for example, oxides, nitrides, and polysilicon materials.

[0052] Subsequently, the vaporized or aerosolized precursor is physically or chemically adsorbed onto the substrate using standard techniques related to CVD, ALD, or similar deposition processes.

[0053] Next, the physically or chemically adsorbed tin compound is pulsed with water (preferably as vapor) to remove hydrolytically unstable substituents and replace them with hydroxyl groups (hydrolysis), forming an organostannasesquioxane (organotin oxide hydroxide) coating. In the subsequent step (irradiation), the adsorbed coating is exposed to radiation (preferably EUV) at a wavelength that breaks the Sn-C bond. Approximately 50 mJ / cm² 2 More preferably 10 mJ / cm² 2Irradiation at a maximum energy level below a certain threshold is used to avoid damage to the substrate. Ultimately, all Sn-C bonds are replaced by Sn-O bonds formed simultaneously with or after irradiation by exposure to oxygen or water in the ambient air.

[0054] In particular, strong absorption of extreme ultraviolet light associated with tin is observed at 13.5 nm. Most organic parts bonded to tin exhibit strong absorption of ultraviolet light at a wavelength of 193 nm and relatively strong absorption up to 230 nm. Therefore, the appropriate wavelength for irradiation is in the range of 13.5–280 nm, including EUV and deep UV. Sufficient energy absorption at these wavelengths leads to the cleavage of the metal-organic bond. Simultaneously with or after the cleavage reaction, additional oxobridges between tin atoms are formed by oxidation, hydrolysis, or hydroxyl substitution reactions.

[0055] A second method for forming an oxostanate film according to an aspect of the present disclosure includes the steps of: preparing a substrate; coating the substrate with a solution of stannatran having formula (I) or azastannatran having formula (II); drying and / or heating the coated substrate; irradiating the coated substrate; and oxidizing the irradiated film or exposing it to water / moisture in the ambient air to form an oxostanate film on the substrate. The resulting film has high purity and is free from dialkyltin compound contamination.

[0056] Suitable substrates are described previously. Solutions of stannatran or azastannatran can be prepared in any solvent known or developed in the art, such as an alcohol such as ethanol (currently preferred) or an aprotic solvent such as THF. The concentration of stannatran or azastannatran in the solvent can be determined by routine experiment, but may be, for example, about 50 to 20% by mass, preferably about 10 to 15% by mass. Any known method for coating the solution onto the substrate, such as immersion coating or spin-on method, may be used.

[0057] The coated substrate is dried at room temperature for a sufficient amount of time, as determined by routine experiments such as overnight drying, or by heating (annealing) to approximately 100°C to 150°C, preferably approximately 120°C to 125°C, to perform thermal conversion. Finally, the coated substrate is irradiated as described above and then exposed to oxygen or moisture in the ambient air to form an oxostanate film.

[0058] While we do not wish to be bound by theory, the currently claimed method and the condensation process of tin-hydroxyl groups for forming stannoxane bonds are considered to result in higher density films, which are desirable at some levels, but may also result in shrinkage and strain that affect the fidelity of the lithography process or induce stress cracking in continuous films. Therefore, films prepared by the method described herein achieve the objective of reducing film shrinkage after radiation exposure. However, other critical performance requirements, including sufficient optical cross-section, film formation on the substrate, dose sensitivity (photosensitivity), storage stability (thermal stability), and volatile components (gas release during exposure or inherent to the compound), must be met. Each of these requirements is described in detail below.

[0059] <High optical cross-sectional area> Tin-oxocluster / polymer materials have proven to be promising EUV resists. In particular, the hydroxy-terminated SnOx underlayer on the surface of the substrate material enhances radiation absorption during imaging layer irradiation, generating secondary electrons from the substrate to further collect additional EUV photons, making the EUV patterning process more sensitive and reducing the required EUV dose for imaging layer exposure. Among the elements of the periodic table, tin has a particularly high optical cross-section.

[0060] <Film formation - Substrate reactivity> Metal-organic (RMX3) compounds must contain a hydrolyzable ligand-metal linkage, where X is the ligand having a hydrolyzable MX linkage. In the compounds described herein, R is an alkyl group (R1), and X represents three nitrogen bridges or three oxygen bridges. In particular, suitable organotin compounds must be able to form films / polymers / clusters on the wafer surface by CVD, ALD, or spin-on. If coating or deposition is a condensed-phase spin-on, clusters may form in the liquid precursor before deposition, which typically results in greater shrinkage.

[0061] <Dose sensitivity (photosensitivity)> Film imaging layers of SnOx thin films containing alkyl groups or with alkyl groups at their termini are selected so that they undergo tin-carbon bond cleavage, such as beta-hydride elimination, upon irradiation with EUV light. Therefore, the R group of cyclic tin compounds is considered to play an important role as UV sensitivity in EUV resist materials. In the EUV patterning process, alkyl groups may be cleaved, leaving Sn-H bond regions, while the unexposed surface remains alkyl-terminated. After exposure to EUV, the film undergoes changes, namely the loss of organic pendant substituents bonded to metal atoms in low-density M-OH-rich materials, but not limited to these, allowing for their cross-linking to higher-density MOM-bonded metal oxide materials. The Sn-H bond, which may be described as a tin hydride, is oxidatively and hydrolyzably sensitive and forms oxides. The hydrolysis reaction of tin hydrides produces hydrogen, which is a volatile byproduct but does not act as an impurity.

[0062] <Storage stability> Tin compounds have a strong tendency to undergo disproportionation reactions, also known as the Kocheshkov homogenization reaction. This reaction accelerates with increasing temperature. Storage stability at temperatures suitable for semiconductor production lines, approximately 20-35°C, is highly desirable. The material's performance implies a requirement for moisture reactivity, which means its sensitivity to moisture. Therefore, storage stability must be considered when supplying materials and products for long-term storage.

[0063] <Volatile components> Tin compounds must be volatile enough to be transported to the substrate by vapor deposition, but volatile components that are not reactive with the substrate must be minimized because they diffuse into non-target areas. Typical sources of these volatile components are non-homogenization byproducts formed during homogenization and radiation exposure during manufacturing or storage.

[0064] The disclosure also relates to a method for forming a patterned film, comprising the steps of preparing an oxostanate film as described herein and exposing the film to discontinuous radiation by rasterizing with an electron beam or laser or by lithography masking.

[0065] The disclosure also relates to a method for forming a continuous film, comprising the steps of preparing an oxostanate film as described herein and exposing the film to blanket exposure using a suitable lithography mask to obtain an optically transparent oxostanate conductive film.

[0066] The present invention will now be described in relation to the following non-limiting embodiments. [Examples]

[0067] (Example 1: Synthesis of 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane) [ka]

[0068] Under an inert atmosphere, 124 g (0.65 mol) of triisopropanolamine and 235 mL of methanol were placed in a 2 L four-neck round-bottom flask equipped with a mechanical stirrer, a pot thermometer, a thermowell, and an addition funnel. A 25% w / w solution of sodium methoxide in 421 g (1.95 mol) of methanol was added to the flask. Next, a solution of 183 g of n-BuSnCl3 (0.65 mol) in 550 mL of toluene was added dropwise to the flask over 1 hour while maintaining the pot temperature below 40 °C. The progress of the reaction was 119 monitored by Sn NMR. After the reaction was complete, the reaction mixture was stripped to a pot temperature of 120 °C, and the resulting concentrate was filtered through an air-free filter. The product was purified by fractional distillation using a Vigreux column under reduced pressure (isolated at 136–139 °C, 0.5 torr), and 147 g (61%) of a thick pale yellow oil was obtained. The product was 1 confirmed by H and 119 Sn NMR spectroscopy as a pair of diastereomers having a ratio of approximately 3:1 and having the properties shown in Table 1. 119 By Sn NMR, only dialkyltin species at a concentration of less than 0.1% were observed.

[0069] UV exposure : The product was exposed to illumination for 8 hours, and no traces of decomposition were 119 observed by either Sn or 1 H NMR spectra. No signs of decomposition of the product sample were observed. 119 By Sn NMR, only dialkyltin species at a concentration of less than 0.1% were observed.

[0070] heat exposure : The product was exposed to heat at 35 °C for 1 week, and no traces of decomposition were 119 observed by either Sn or 1 H NMR spectra. No signs of decomposition of the product sample were observed. 119 By Sn NMR, only dialkyltin species at a concentration of less than 0.1% were observed.

[0071] [Table 1]

[0072] (Example 2: Synthesis of 1-(3,3,3-trifluoropropyl)-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane) [ka]

[0073] Under an inert atmosphere, 38.25 g (0.20 mol) of triisopropanolamine and 73 mL of methanol were placed in a 500 mL three-necked round-bottom flask equipped with a magnetic stirrer, pot thermometer, thermowell, and addition funnel. A 25% w / w solution of sodium methoxide in 130 g (0.60 mol) of methanol was added to the flask. Next, while maintaining the pot temperature below 40°C, 64.42 g (0.20 mol) of CF3CH2CH2SnCl3 solution in 162 mL of toluene was added dropwise to the flask over 1 hour. The reaction proceeded as follows: 119 The reaction was monitored by Sn NMR. After the reaction was complete, the reactants were stripped to a pot temperature of 120°C, and the resulting concentrate was filtered through an air-free filter. The product was purified by vacuum distillation (isolated at 0.3 torr at 126-128°C) to obtain 56.6 g (70%) of a crystalline pale yellow solid. The product was, 1 H and 119 Sn NMR spectroscopy confirmed them as a pair of diastereomers with a ratio of approximately 3:1, possessing the properties shown in Table 2. 119 Sn NMR revealed only dialkyltin species at concentrations of less than 0.1%.

[0074] UV exposure The product in a saturated cyclohexane solution was exposed to light for 8 hours, and no traces of decomposition were found. 119 Sn or 1 No degradation was observed in either of the 1H NMR spectra. No signs of degradation of the product sample were observed. 119 Sn NMR revealed only dialkyltin species at concentrations of less than 0.1%.

[0075] heat exposure The product in a saturated cyclohexane solution was exposed to heat at 35°C for one week, and no traces of decomposition were found. 119 Sn or 1 No degradation was observed in either of the 1H NMR spectra. No signs of degradation of the product sample were observed. 119 Sn NMR revealed only dialkyltin species at concentrations of less than 0.1%.

[0076] [Table 2]

[0077] (Example 3: Synthesis of 1-isopropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane) [ka]

[0078] Under an inert atmosphere, 57.0 g (0.194 mol) of isopropyltris(dimethylamino)tin was placed in a 200 mL three-necked round-bottom flask equipped with a magnetic stirrer, pot thermometer, thermowell, and addition funnel. While maintaining the pot temperature below 40°C, a solution of 37.02 g (0.194 mol) of triisopropanolamine in 43 mL of toluene was added dropwise to the flask. The reaction mixture was stirred for 2 hours. 119 The reaction was monitored by Sn-NMR. After completion, the product was isolated from the reaction mixture by vacuum distillation (0.3 torr, 108-110°C) to obtain 41.1 g (65%) of a white crystalline solid with a melting point of 93-94°C. The product was, 1 H and 119 Sn NMR spectroscopy confirmed them as a pair of diastereomers with a ratio of approximately 2.5:1, possessing the properties shown in Table 3. 119 Sn NMR revealed only dialkyltin species at concentrations of less than 0.1%.

[0079] UV exposure The product in a saturated cyclohexane solution was exposed to light for 8 hours, and no traces of decomposition were found. 119 Sn or1 No degradation was observed in either of the 1H NMR spectra. No signs of degradation of the product sample were observed. 119 Sn NMR revealed only dialkyltin species at concentrations of less than 0.1%.

[0080] heat exposure The product in a saturated cyclohexane solution was exposed to heat at 35°C for one week, and no traces of decomposition were found. 119 Sn or 1 No degradation was observed in either of the 1H NMR spectra. No signs of degradation of the product sample were observed. 119 Sn NMR revealed only dialkyltin species at concentrations of less than 0.1%.

[0081] [Table 3]

[0082] (Example 4: Synthesis of 1-isopropyl-2,5,8,9-tetraaza-1-stannabicyclo[3.3.3]undecane) [ka]

[0083] Under an inert atmosphere, 132.30 g (0.45 mol) of isopropyltris(dimethylamino)tin was placed in a 500 mL three-necked round-bottom flask equipped with a magnetic stirrer, pot thermometer, thermowell, and addition funnel. While maintaining the pot temperature below 40°C, 65.80 g (0.45 mol) of tris(2-aminoethyl)amine solution in 75.90 mL of toluene was added dropwise to the flask. The reaction mixture was stirred for 2 hours. 119 The reaction was monitored by Sn-NMR. After completion (when gas release stopped), 90% of the solvent in the reaction mixture was removed by vacuum distillation to obtain a solid product mixture. Dry hexane was added to precipitate 107.4 g (83.78%) of the title compound, a pale yellow solid with a melting point of 58°C. The product was: 1 H and 119 The properties were confirmed by Sn NMR spectroscopy and are shown in Table 4. 119Sn NMR revealed only dialkyltin species at concentrations of less than 0.1%.

[0084] [Table 4]

[0085] (Example 5: Surface modification of silicon wafers with 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane) All operations were performed under ambient laboratory conditions. The silicon wafers were cleaned and dried in a dry box using a hot plate set to 120°C (or room temperature). 0.20 g of 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane, as prepared in Example 1, was placed in 15.1 g of anhydrous EtOH and stirred at 45°C for 30 minutes. Two samples were prepared. Sample A was immersed in the solution for 5 minutes and dried at 120°C for 5 minutes, while Sample B was immersed in the solution for 5 minutes and then dried overnight at room temperature. The XPS spectra of Samples A and B are shown in Figures 1a and 1b.

[0086] Figure 1a shows the XPS spectrum of a silicon wafer coated with 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane after immersion for 5 minutes and drying at 120°C for 5 minutes, and Figure 1b shows the XPS spectrum of a silicon wafer coated with 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane after immersion for 5 minutes and drying overnight at room temperature. These spectra demonstrate that the oxostanate film was successfully deposited on the silicon wafer.

[0087] (Example 6: Surface modification of silicon wafers with 1-isopropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane) All operations were performed under ambient laboratory conditions. The silicon wafers were cleaned and dried in a dry box using a hot plate set to 120°C (or room temperature). 0.20 g of 1-isopropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane, as prepared in Example 3, was placed in 15.1 g of anhydrous EtOH and stirred at 45°C for 30 minutes. Two samples were prepared. Sample A was immersed in the solution for 5 minutes and dried at 120°C for 5 minutes, while Sample B was immersed in the solution for 5 minutes and then dried overnight at room temperature. The XPS spectra of Samples A and B are shown in Figures 2a and 2b.

[0088] Figure 2a shows the XPS spectrum of a silicon wafer coated with 1-isopropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane after immersion for 5 minutes and drying at 120°C for 5 minutes, and Figure 2b shows the XPS spectrum of a silicon wafer coated with 1-isopropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane after immersion for 5 minutes and drying overnight at room temperature. These spectra demonstrate that the oxostanate film was successfully deposited on the silicon wafer.

[0089] (Example 7: Surface modification of a silicon wafer with 1-(3,3,3-trifluoropropyl)-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane) All operations were performed under ambient laboratory conditions. The silicon wafers were cleaned and dried in a dry box using a hot plate set to 120°C (or room temperature). 0.20 g of 1-(3,3,3-trifluoropropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane, as prepared in Example 2, was placed in 15.1 g of anhydrous EtOH and stirred at 45°C for 30 minutes. Two samples were prepared. Sample A was immersed in the solution for 5 minutes and dried at 120°C for 5 minutes, while Sample B was immersed in the solution for 5 minutes and then dried overnight at room temperature. The XPS spectra of Samples A and B are shown in Figures 3a and 3b.

[0090] Figure 3a shows the XPS spectrum of a silicon wafer coated with 1-(3,3,3-trifluoropropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane) after immersion for 5 minutes and drying at 120°C for 5 minutes, and Figure 3b shows the XPS spectrum of a silicon wafer coated with 1-(3,3,3-trifluoropropyl)-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane after immersion for 5 minutes and drying overnight at room temperature. These spectra demonstrate that the oxostanate film was successfully deposited on the silicon wafer.

[0091] Those skilled in the art will understand that modifications can be made to the above embodiments without departing from the broader concept of the invention. Therefore, it will be understood that the invention is not limited to the specific embodiments disclosed, but is intended to encompass modifications within the spirit and scope of the invention as defined by the appended claims.

Claims

1. Equation (I): 【Chemistry 1】 (In the formula, R １ R is a substituted or unsubstituted linear or branched alkyl group having 1 to about 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to about 20 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to about 10 carbon atoms, and each R ２ R is independently a substituted or unsubstituted linear or branched alkyl group having hydrogen or 1 to about 10 carbon atoms, wherein at least one R ２ (Provided that it is not hydrogen) A stanator that has a stanator.

2. Formula 1-n-butyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane: 【Chemistry 2】 A stannar according to claim 1, having the following characteristics.

3. Formula 1-(3,3,3-trifluoropropyl)-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane: 【Transformation 3】 A stannar according to claim 1, having the following characteristics.

4. Formula 1-isopropyl-3,7,10-trimethyl-2,8,9-trioxa-5-aza-1-stannabicyclo[3.3.3]undecane: 【Chemistry 4】 A stannar according to claim 1, having the following characteristics.

5. Stannatran according to any one of claims 1 to 4, having a purity of at least about 99.9%.

6. Stannatran according to any one of claims 1 to 5, containing less than approximately 0.1% of a dialkyltin compound.

7. A method for forming stannatran according to any one of claims 1 to 6, Alkali metal alkoxides with triisopropanolamine and formula R １ SnCl ３ A method comprising the step of reacting with an alkyltin trichloride compound having [a specific characteristic].

8. A method for forming stannatran according to any one of claims 1 to 6, Formula R １ Sn(NMe ２ ) ３ A method comprising the step of reacting an alkyltris(dimethylamino)tin compound having with triisopropanolamine.

9. Formula (II): 【Transformation 5】 (wherein, R １ is a substituted or unsubstituted, linear or branched alkyl group having 1 to about 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to about 20 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to about 10 carbon atoms, and each R ２ is independently hydrogen or a substituted or unsubstituted, linear or branched alkyl group having 1 to about 10 carbon atoms, and each R ３ is independently hydrogen or a substituted or unsubstituted, linear or branched alkyl group having 1 to about 10 carbon atoms, provided that at least one R ３ is not hydrogen) Azastan Natran, which possesses this.

10. Azastannatran according to claim 9, having a purity of at least about 99.9%.

11. Azastannatran according to claim 9 or 10, containing less than approximately 0.1% of a dialkyltin compound.

12. A method for forming azastannatran according to any one of claims 9 to 11, Formula R １ Sn(NMe ２ ) ３ A method comprising the step of reacting an alkyltris(dimethylamino)tin compound having with tris(2-aminoethyl)amine.

13. A method for forming an oxostanate membrane, The process of preparing the circuit board, A step of coating the substrate with a stannatran solution according to any one of claims 1 to 6, A step of drying and / or heating the coated substrate, The process of irradiating the coated substrate, A step of exposing the irradiated substrate to oxygen or moisture to form an oxostanate film on the substrate. Methods that include...

14. A method for forming an oxostanate membrane, The process of preparing the circuit board, A step of coating a substrate with a solution of azastannatran according to any one of claims 9 to 11, A step of drying and / or heating the coated substrate, The process of irradiating the coated substrate, A step of exposing the irradiated substrate to oxygen or moisture to form an oxostanate film on the substrate. Methods that include...

15. A method for forming an oxostanate membrane, A step of vaporizing the stannatran described in any one of claims 1 to 6 or preparing an aerosol thereof, The process of preparing the circuit board, A step of physically or chemically adsorbing vaporized or aerosolized stannatran onto a substrate, A process to form an oxostanate film on a substrate by physically or chemically adsorbing stannatran and subjecting it to a series of hydrolysis and irradiation steps, followed by oxidation or a second hydrolytic exposure. Methods that include...

16. A method for forming an oxostanate membrane, A step of vaporizing azastannatran according to any one of claims 9 to 11 or preparing an aerosol thereof, The process of preparing the circuit board, A step of physically or chemically adsorbing vaporized or aerosolized azastannatran onto a substrate, A process to form an oxostanate film on a substrate by physically or chemically adsorbing azastannatran and subjecting it to a series of hydrolysis and irradiation steps, followed by oxidation or a second hydrolytic exposure. Methods that include...

17. A method for forming a patterned film, comprising the steps of preparing an oxostanate film as defined in claim 13, and exposing the film to discontinuous radiation by rasterizing with an electron beam or laser or by lithography masking.

18. A method for forming a patterned film, comprising the steps of preparing an oxostanate film as defined in claim 14, and exposing the film to discontinuous radiation by rasterizing with an electron beam or laser or by lithography masking.

19. A method for forming a patterned film, comprising the steps of preparing an oxostanate film as defined in claim 15, and exposing the film to discontinuous radiation by rasterizing with an electron beam or laser or by lithography masking.

20. A method for forming a patterned film, comprising the steps of preparing an oxostanate film as defined in claim 16, and exposing the film to discontinuous radiation by rasterizing with an electron beam or laser or by lithography masking.

21. A method for forming a continuous film, comprising the steps of preparing an oxostanate film as defined in claim 13, and exposing the film to blanket exposure using a suitable lithography mask to obtain an optically transparent tin oxide conductive film.

22. A method for forming a continuous film, comprising the steps of preparing an oxostanate film as defined in claim 14, and exposing the film to blanket exposure using a suitable lithography mask to obtain an optically transparent tin oxide conductive film.

23. A method for forming a continuous film, comprising the steps of preparing an oxostanate film as defined in claim 15, and exposing the film to blanket exposure using a suitable lithography mask to obtain an optically transparent tin oxide conductive film.

24. A method for forming a continuous film, comprising the steps of preparing an oxostanate film as defined in claim 16, and exposing the film to blanket exposure using a suitable lithography mask to obtain an optically transparent tin oxide conductive film.

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