Deuterated organotin compounds, synthesis methods, and radiation-induced patterning - Patents.com

Abstract

Organotin compounds are provided that are represented by the formula RSnL3, where R is a deuterated hydrocarbyl group and L is a hydrolyzable ligand. Two different synthetic methods are described for synthesizing these compositions. The first method involves reacting a primary halide hydrocarbyl compound (RX, where X is a halide atom) with an organometallic composition containing a SnL3 residue with a metal cation M, where M is an alkali metal, alkaline earth metal, and / or pseudo-alkaline earth metal (Zn, Cd, or Hg), and L is either an amide ligand to give an alkali metal tin triamide compound or an acetylide ligand to give an alkali metal tin triacetylide, to give the corresponding monohydrocarbyltin triamide (RSn(NR'2)3) or monohydrocarbyltin triacetylide (RSn(C≡CR s )3). Another approach involves reacting a Grignard reagent RMgX with SnL4 in a solution containing an organic solvent to form monoorganotin trialkylamides, monoorganotin trialkoxides, monoorganotin triacetylides, or monoorganotin tricarboxylates. These compositions are useful in patterning by radiation, particularly EUV radiation.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to co-pending U.S. patent application Ser. No. 17 / 682,586 (Jilek et al., filed Feb. 28, 2022, entitled "Deuterated Organotin Compounds, Methods of Synthesis and Radiation Patterning"), which claims priority to co-pending U.S. provisional patent application Ser. No. 63 / 215,720 (Jilek et al., filed Jun. 28, 2021, entitled "Deuterated Organotin Compounds"), which applications are incorporated herein by reference.

[0002] The present invention relates to compositions of mono-organotin triamides, mono-organotin triacetylides, mono-organocarboxylates, or mono-organotin trioxides, where the organic groups are defined as hydrocarbyls containing deuterated residues. The invention also relates to hydrolysis reaction products, syntheses of these compositions, and methods for performing radiation-induced patterning. [Background technology]

[0003] In semiconductor fabrication, many iterative processes are typically required to integrate devices onto a chip. A key process in semiconductor device fabrication is the lithography process, in which a light-sensitive material (called photoresist) is deposited on a substrate and then patterned using radiation. As the demand for higher device performance increases, the need for better photoresists also increases.

[0004] Photoresists generally function by undergoing chemical changes in areas exposed to radiation sources, such as ultraviolet (UV) light, extreme ultraviolet (EUV) light, and electron beams. The chemical changes result in differential development rates between exposed and unexposed areas of the photoresist. Prior art semiconductor device fabrication currently employs EUV radiation, which creates a need for new photoresist materials that maximize the economics of the lithography process. Summary of the Invention [Means for solving the problem]

[0005] One aspect of the present invention relates to organotin compounds of the formula RSnL3, where R is a deuterated hydrocarbon group.

[0006] In another aspect, the invention relates to organotin compounds of the formula (CD3)3CSnL3, where L is a hydrolyzable ligand.

[0007] In another aspect, the invention relates to organotin compounds of the formula CD3SnL3, where L is a hydrolyzable ligand.

[0008] In yet another aspect, the present invention relates to methods for preparing radiation-patternable coatings of deuterated organotin compounds. In particular, the synthesis and formation of such coatings are contemplated.

[0009] In another aspect, the present invention relates to a method for patterning a radiation-sensitive coating comprising at least one deuterated organotin composition. Patterning using EUV radiation is of particular interest. The present invention may also relate to the patterned structures thus obtained.

[0010] In some embodiments, the present invention relates to organotin compounds represented by the formula RSnL3, where R is a deuterated hydrocarbyl group and L is a hydrolyzable ligand.

[0011] In a further aspect, the present invention relates to a method for synthesizing deuterated organotin compositions, which method includes reacting a primary halide hydrocarbyl compound (RX, where X is a halide atom) with an organometallic composition comprising a SnL residue with a metal cation M (where M is an alkali metal, alkaline earth metal, and / or pseudo-alkaline earth metal (Zn, Cd, or Hg) and L is either an amide ligand to give an alkali metal tin triamide compound or an acetylide ligand to give an alkali metal tin triacetylide) to form the corresponding monohydrocarbyltin triamide (RSn(NR'2)3) or monohydrocarbyltin triacetylide (RSn(C≡CR s )3), where the monohydrocarbyl ligand (R) is a deuterated hydrocarbyl group having 1 to 31 carbon atoms and optionally unsaturated carbon-carbon bonds, optional aromatic groups, and optional heteroatoms; R s is SiR"3 or R', where the three R"s are independently H or R', and the R's are independently hydrocarbyl groups having 1 to 31 carbon atoms and optionally unsaturated carbon-carbon bonds, optional aromatic groups, and optional heteroatoms.

[0012] Organometallic compositions containing SnL3 residues with their metal cations M can be synthesized by a method comprising: combining M'L, tin(II) halide (SnX2, X = F, Cl, B, I, or mixtures thereof), and optionally M''OR to form an alkali metal tin composition. 0(wherein M' is Li, Na, K, Cs, or a combination thereof, M'' is Na, K, Cs, or a combination thereof, and L is a dialkylamide (-NR') or acetylide (-C≡CL s ) in an organic solvent to form the organometallic composition with the corresponding residue SnL3, which is a tin triamide (MSn(NR'2)3) or tin triacetylide (MSn(C≡CL s )3), where M is M″ if M″ is present or M′ if M″ is absent, and L s is SiR"3 or R', where the three R"s are independently H or R', and R 0 and R' are independently hydrocarbyl groups having 1 to 31 carbon atoms and optionally unsaturated carbon-carbon bonds, optional aromatic groups, and optional heteroatoms.

[0013] In another aspect, the present invention relates to a method for forming a monoorganotin triamide compound, the method comprising reacting a Grignard alkylating agent RMgX with Sn(NR') in a solution comprising an organic solvent, where R is a hydrocarbyl group having 1 to 31 carbon atoms and at least one deuterium atom, where X is a halogen, and where R' is a hydrocarbyl group having 1 to 10 carbon atoms.

[0014] In another aspect, the present invention relates to a method for synthesizing monoorganotin trialkoxides, monoorganotin triacetylides, or monoorganotin tricarboxylates, comprising reacting a Grignard alkylating agent RMgX with SnL4 in a solution containing an organic solvent, where R is a hydrocarbyl group having 1 to 31 carbon atoms, where X is a halogen, and where R' is a hydrocarbyl group having 1 to 10 carbon atoms, and L is R'COO, CCR', or OR', where R' has 1 to 10 carbon atoms and optional heteroatoms. In these reactions, R may or may not be deuterated. [Brief explanation of the drawings]

[0015] [Figure 1A] 2H NMR spectrum of d9-tBuSn(Ot-Bu)3 in C6D6. [Figure 1B] 13C NMR spectrum of d9-tBuSn(Ot-Bu)3 in C6D6. [Figure 1C] 119Sn NMR spectrum of d9-tBuSn(Ot-Bu)3 in C6D6. [Figure 2A] 2H NMR spectrum of D3MeSn(CCPh)3 in C6D6. [Figure 2B] 119Sn NMR spectrum of D3MeSn(CCPh)3 in C6D6. [Figure 3A] 119Sn NMR spectrum of D3MeSn(t-pentoxide)3 in C6D6. [Figure 3B] 1H NMR spectrum of D3MeSn(t-pentoxide)3 in C6D6. [Figure 4] 1 is a series of electron microscope images of line-space patterns for d9-tBuSn(Ot-Amyl)3 resist processed at selected post-exposure bake temperatures. [Figure 5]A series of stacked FTIR spectra of films prepared using two different d9-tBuSn(Ot-Bu)3 formulations and subjected to selected heating conditions after deposition. [Figure 6] A series of contrast curves generated using a preparation of non-deuterated tBuSn(Ot-Bu)3 and two different preparations of d9-tBuSn(Ot-Bu)3. DETAILED DESCRIPTION OF THE INVENTION

[0016] Organometallic photoresists incorporating deuterated ligands have been developed to exploit the potential benefits of isotope effects. Specifically, perdeuterated ligands are disclosed, in which multiple hydrogen atoms are replaced with multiple deuterium atoms. Two different alternative synthetic routes are described and exemplified. Patterning using the exemplified deuterated organometallic resists yields desirable results, making them promising for high-resolution patterning resists. Substitution of hydrogen atoms with deuterium can provide different performance with different reaction rates as a result of kinetic isotope effects, as well as different analytical properties that can be useful in purification and / or characterization. Deuterium enrichment can be site-specific, or all hydrogen atoms in the composition can be replaced (perdeuterated). Tin-based organometallic patterning compositions are important patterning compositions for achieving high-resolution EUV patterning. Desired patterning results using deuterated photoresists are described.

[0017] Organometallic photoresists, especially those based on organotin materials, have been found to function as high-performance radiation-patterning compositions, particularly EUV photoresists, that allow for high-fidelity and high-resolution patterning. These materials can generally be made to function as positive-acting photoresists (in which the exposed areas are selectively removed during development) or negative-acting photoresists (in which the exposed areas remain after development) by appropriate selection of the development process or solvent.

[0018] It is believed that exposing organotin materials to UV or EUV radiation and then processing causes cleavage of Sn-C bonds, forming condensed networks containing Sn-O-Sn and Sn-OH bonds in the exposed areas. The increased concentration of these bonds results in a material that is more concentrated and hydrophilic than the starting material, thereby creating a large chemical and development contrast between exposed and unexposed areas.

[0019] Radiation-sensitive organotin compositions useful as high-resolution and high-sensitivity photoresists are described in the following patents by Meyers et al.: U.S. Pat. No. 9,310,684 (entitled "Organometallic Solution-Based High Resolution Patterning Composition") and U.S. Pat. No. 10,228,618 (hereinafter referred to as the '618 patent) (entitled "Organotin oxide hydroxide patterning compositions, precursors, and patterning") (both of which are incorporated herein by reference). Generally, radiation-sensitive organotin compositions include organic ligands bonded to Sn atoms via Sn—C and / or Sn-carboxylate bonds. The present disclosure describes novel deuterium-enriched organotin compositions that have been found to be capable of exhibiting improved patterning properties over non-enriched organotin compositions.

[0020] In some embodiments, the deuterium-enriched organotin composition has the formula R D SnL3, where R D is a hydrocarbyl group (alkyl, cycloalkyl, alkenyl, alkynyl, aryl) in which at least one hydrogen atom has been replaced with deuterium. In a further embodiment, R D However, all the hydrogen ( 1 H) atom is deuterium ( 2 H), such as R D may be -CD3, -CD(CD3)2, or -C(CD3)3C, where D is deuterium and - is the bond to Sn. As described in more detail below, the hydrocarbyl group may further contain other heteroatoms. Applicants have developed several synthetic routes to deuterated organotin compounds with hydrolyzable ligands, which are described in more detail below.

[0021] Without wishing to be bound by theory, it is believed that deuterium atoms, e.g. 2 Substituting H into radiation-sensitive organotin compositions is believed to be advantageous due to the kinetic isotope effect of the heavy atom. 2 Some reaction pathways involving H 1 Reaction pathways involving H tend to be less favorable kinetically than reaction pathways involving H. Therefore, to improve reaction-based pathways and processes such as those involving: 1 H atoms were substituted 2 The inclusion of H atoms may be desirable due to: thermal decomposition of Sn-C bonds, sensitivity to out-of-band radiation and / or photon shot noise, defect generation, etch rate, and / or smearing (which refers to residue remaining after patterning). 2 1 shows EUV exposure of H-enriched organotin photoresist.

[0022] Deuterium-enriched materials may be useful in numerous analytical methods, particularly those that distinguish based on mass or nuclear spin, such as chromatography, infrared spectroscopy, mass spectrometry, nuclear magnetic resonance, etc. Those skilled in the art will recognize the analytical advantages of deuterium-enriched materials compared to their non-deuterated analogs.

[0023] The compositions described herein are useful as precursors for forming radiation-patternable coatings, and for converting the precursors to other useful compositions, such as compositions with different hydrolyzable ligands or cluster-like compositions with Sn-O-Sn bonds and / or Sn-OH groups. As noted above, the photosensitivity of organotin materials derives from the nature of the Sn-C bond, and therefore it is generally desirable for the Sn-C bond to remain intact during processing of the precursor to a coating. Hydrolyzable ligands have little effect on photosensitivity because they are generally hydrolyzed prior to irradiation and are generally chosen for desired processing, such as further purification, mode of deposition, stability, and handleability.

[0024] As described herein, the hydrolyzable ligand is a ligand that promotes the reaction of water with an organotin molecule to give an organotin oxide hydroxide composition, as shown in the following reaction: RSnL3+2H2O → RSnOOH+3HL (1).

[0025] For purposes of this disclosure, the reactions described above, and the following discussion, R and R D The groups -NR', -OR', and -R'COO are to be understood as interchangeable groups. RSnOOH compositions are typically used for radiation patterning, which means that the L of the hydrolyzable ligand is removed by hydrolysis during processing. Some examples of suitable hydrolyzable ligands are -NR', -OR', -R'COO, and -NR'COO. -and -CC(R'), where R' is a silyl or hydrocarbyl group having 30 or fewer carbon atoms, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, tert-amyl, --(Si(CH3)3), -Ph(C6H5), and the like.

[0026] Hydrolysis of the RSnL3 compositions described above generally affords hydroxide- and oxide-rich reaction products, where two or more RSn residues condense to form Sn-O and Sn-OH bonds, such as the well-known "football" cluster [(RSn) 12 O 14 (OH)6](OH)2. As described below, hydrolysis of instant RSnL3 compositions can be used to prepare radiation-patternable coatings. In the coatings, RSnOOH compositions are generally believed to form oxo / hydroxo networks with both Sn-OH and Sn-O-Sn residues. To form radiation-patternable coatings, the hydrolysis can occur during or after the formation of the coating, but generally before irradiation. The coatings can be deposited using solution or vapor-phase methods.

[0027] R forms a carbon-tin bond, where the carbon bonded to the tin is sp 3 or sp 2 form hybrid orbitals, and R includes at least one deuterium atom and may optionally include unsaturated or aromatic carbon-carbon residues and / or other heteroatoms that are not carbon or hydrogen / deuterium. As noted above, for convenience and consistency in the art, R may interchangeably refer to alkyl, organo, or hydrocarbyl ligands with corresponding substituents and bonding structures.

[0028] In some embodiments, for some pattern-forming compositions, hydrocarbyl R ligands may be desirable, where the compound (which effects hydrolysis of the hydrolyzable ligand) generally has an R 1 R 2 R 3 CSnO (2-(z / 2)-(x / 2)) (OH) x where R 1 , R 2 , and R 3 are independently hydrogen / deuterium or a hydrocarbyl group having 1 to 10 carbon atoms, while R 1 , R 2 , and R 3 collectively contain at least one deuterium atom. In some embodiments, it may be desirable for R to be perdeuterated, i.e., all hydrogen atoms are replaced by deuterium, while in other embodiments, only a portion of the hydrogen atoms are replaced by deuterium. This representation of the hydrocarbyl ligand R is applicable to other embodiments as well, and generally refers to R 1 R 2 R 3 CSn(L)3, where L corresponds to a hydrolyzable ligand, such as an alkoxide (hydrocarbyloxide), carboxylate, acetylide, or amide residue. In some embodiments, R 2 and R 3 and R can form a cyclic alkyl residue. 1 It is also possible for the cyclic residue to be joined to other groups. Suitable branched alkyl ligands include, for example, isopropyl (R 1 and R 2 is methyl and R 3 is hydrogen or deuterium), tert-butyl (R 1 , R 2 , and R 3 is methyl), tert-amyl (R 1 and R 2 is methyl and R 3is -CH2CH3), sec-butyl (R 1 is methyl and R 2 is -CH2CH3, and R 3 is hydrogen or deuterium), neopentyl (R 1 and R 2 is hydrogen or deuterium, and R 3 is —C(CH3)3), cyclohexyl, cyclopentyl, cyclobutyl, and cyclopropyl. One or more hydrogen atoms in these branched alkyl ligands may be replaced with deuterium. In other embodiments, the hydrocarbyl group may include an aryl or alkenyl group, such as benzyl or allyl, or an alkynyl group. In further embodiments, suitable R groups may include hydrocarbyl groups substituted with heteroatom functional groups, such as cyano, thio, ether, keto, ester, or halogenated groups, or combinations thereof. As is customary in the art, a hydrocarbyl group may be referred to as an alkyl group even if the group contains unsaturated bonds, aryl groups, heteroatoms, etc. In some embodiments, all hydrogen atoms may be replaced with deuterium to form a perdeuterated group.

[0029] It is desirable to convert the reaction product containing a trialkylamide, triacetylide, or other hydrolyzable ligand to an organotin trialkoxide for use in a solution-deposited patterning composition. As described in more detail below, this reaction is typically carried out by purification by distillation followed by reaction with the corresponding alcohol, although the reaction with the alcohol can also be carried out without first purifying the trialkylamide / trialkylacetylide reactant. An additional solvent in addition to the alcohol may or may not be used. The reaction product, an organotin trialkoxide, is typically an oil or low-melting solid that can be purified by distillation. These steps are described further below, and specific reaction products are illustrated in the examples below. While conversion of the precursor composition to a trialkoxide is not required to form a coating precursor, organotin trialkoxides can be convenient precursors for deposition because the reaction product, e.g., an alcohol, after hydrolysis and coating formation has mild volatility.

[0030] After preparing the desired organotin precursor, the precursor can be dissolved in a suitable solvent, e.g., an organic solvent, such as an alcohol, aromatic or aliphatic hydrocarbon, ester, or a combination thereof, to form a precursor solution. Particularly suitable solvents include, for example, aromatic compounds (e.g., xylene, toluene), ethers (anisole, tetrahydrofuran), esters (propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate), alcohols (e.g., 4-methyl-2-pentanol, 1-butanol, methanol, isopropyl alcohol, 1-propanol), ketones (e.g., methyl ethyl ketone), mixtures thereof, and the like. Generally, the choice of organic solvent can be influenced by factors such as solubility parameters, volatility, flammability, toxicity, viscosity, and the potential for chemical interaction with other processing materials. After dissolving and combining the components of the solution, the properties of the chemical species may change as a result of partial in situ hydrolysis, hydration, and / or condensation.

[0031] The organotin precursor can be dissolved in a solvent to obtain a suitable Sn concentration for forming a coating of suitable thickness for processing. The concentration of the species in the precursor solution can be selected to provide the desired physical properties of the solution. In particular, a low overall concentration can provide desirable solution properties for certain coating approaches, such as spin coating, which can achieve thinner coatings using reasonable coating parameters. Thinner coatings are desirable for achieving ultrafine patterning and reducing material costs. Generally, the concentration can be selected to optimize a selected coating approach. Coating performance is discussed in more detail below. Tin concentrates typically range from about 0.005 M to about 1.4 M, from about 0.02 M to about 1.2 M in a further embodiment, and from about 0.1 M to about 1.0 M in a further embodiment. As those skilled in the art will appreciate, additional ranges of tin concentrations within the ranges explicitly stated above are contemplated and are within the present disclosure.

[0032] In some embodiments, the improved photosensitive precursor composition comprises one or more organotin compositions, such as R n SnX 4-n and their hydrolyzates, where R is selected from the various residues detailed herein and explicitly detailed above. Such blend solutions can be adjusted for optimization based on various performance considerations, such as solution stability, coating uniformity, and patterning performance. Blended compositions can be prepared by blending two or more organotin compositions, such as R n SnL 4-n(where L is a hydrolyzable ligand) can be obtained by combing in the presence or absence of a solvent. For example, neat RSnL3 can be combined with neat R'SnL3 to form a blended precursor. Optionally, the blended composition can then be diluted into a solvent. Alternatively, each individual organotin composition can be diluted in a desired solvent to form an individual organotin solution, and then the individual organotin solutions can be combined to form the blended solution. Generally, the hydrolyzable ligands can be the same or different for each organotin component in the overall blended composition. In some embodiments, the improved photosensitive composition can include a specific desired component of at least 1 mol % Sn in the blended solution, in further embodiments at least 10 mol % Sn of the blended solution, in further embodiments at least 20 mol % Sn of the blended solution, and in further embodiments at least 50 mol % Sn of the blended solution. Additional ranges of mol % of the improved photosensitive composition within the stated ranges of the blend solutions are contemplated and are within the present disclosure.

[0033] Generally, due to their high vapor pressure, the organotin compositions described herein may be useful as precursors for forming coatings via vapor deposition. Vapor deposition methods generally include chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), and modifications thereof. In a typical vapor deposition process, the organotin compositions can be reacted with small molecule gas-phase reactants, such as HO, O, HO, O, CHOH, HCOOH, CHCOOH, etc., which serve as sources of O and H to produce radiation-sensitive organic tin oxide and oxide hydroxide coatings. Organotin compositions containing alkylamides or alkoxides as hydrolyzable ligands may be particularly desirable for use in vapor deposition methods to form organic tin oxide / hydroxide coatings. Deposition of radiation-patternable organotin coatings is described in published PCT application WO 2019 / 217749 (Wu et al., entitled "Methods for Making EUV Patternable Hard Masks"), which is incorporated herein by reference, and further in the previously cited '618 patent. The production of radiation-sensitive organotin coatings can generally be achieved by reacting a volatile organotin precursor, RSnL3, with small gas-phase molecules. The reaction involves hydrolysis / condensation of the organotin precursor to hydrolyze the hydrolyzable ligands, while leaving the Sn-C bonds substantially intact.

[0034] In relation to a typical process for radiation-based patterning, e.g., an extreme ultraviolet (EUV) lithography process, a photoresist material is deposited or coated as a thin film on a substrate, pre-exposure baked, exposed with a pattern of radiation to create a latent image, post-exposure baked, and then developed with a liquid, typically an organic solvent, or using a dry development method to create a developed pattern of the resist. Fewer steps can be used, or additional steps can be used to remove residue and improve pattern fidelity, if desired.

[0035] The thickness of the radiation-patternable coating can depend on the desired process. For use in single-patterning EUV lithography, the coating thickness is generally selected to provide a pattern with few defects and good pattern reproducibility. In some embodiments, a suitable coating thickness is between 0.5 nm and 100 nm, in further embodiments, about 1 nm to 50 nm, and in further embodiments, about 2 nm to 25 nm. As will be appreciated by those skilled in the art, additional ranges of coating thickness are contemplated and are within the scope of the present disclosure. For radiation-patternable coatings prepared by vapor deposition, the coating thickness can generally be controlled by appropriately selecting the reaction time or number of cycles of the process.

[0036] The substrate generally provides a surface onto which a coating material can be deposited, and may be comprised of multiple layers, of which the surface refers to the top layer. The substrate is not particularly limited and may include any suitable material, such as silicon, silica, other inorganic materials, e.g., ceramics, and polymeric materials.

[0037] After deposition to form a radiation-patternable coating, further processing can be employed prior to exposure to radiation. In some embodiments, the coating can be heated between 30°C and 300°C, in further embodiments between 50°C and 200°C, and in further embodiments between 80°C and 150°C. The heating can be carried out in some embodiments for about 10 seconds to about 10 minutes, in further embodiments for about 30 seconds to about 5 minutes, and in further embodiments for about 45 seconds to about 2 minutes. Additional ranges of temperatures and heating times within the explicit ranges above are contemplated and envisioned.

[0038] Synthesis of deuterium-enriched compositions Applicants have developed several suitable synthetic methods for synthesizing heavy atom (deuterium)-enriched organotin compositions. The method should be selected based on practical considerations, such as the purity and yields achieved by various methods, the convenience of the procedures, and the availability of easy-to-use starting materials. For example, in the general synthesis of monoalkyltin trialkylamides, desirable results have been obtained when the alkylating agent is a Grignard reagent, a diorganozinc reagent, or a monoorganozinc amide. These synthetic methods can produce monoalkyltin triamides low in polyalkyl impurities, which can be used to form resists or can be further purified to achieve even lower impurity levels. In a further method developed by Applicants, the alkylating agent is an alkyl halide, which reacts with a tin composition complexed with alkali, alkaline, and / or pseudo-alkaline metal ions.

[0039] The synthesis of deuterated tin compositions is exemplified below. In one approach, the alkylating agent is a Grignard reagent. Grignard reagents are organomagnesium halides. Specifically, the Grignard reagent in the described reaction can be RMgX, where X is a halide, typically Cl, Br, or I, and R is as defined above. Grignard reagents can be commercially available or synthesized using known methods. Commercial sources include American Elements Company, Sigma-Aldrich, and many other suppliers.

[0040] In the Grignard approach, the alkylating agent selectively replaces the amide group of the tin tetraamide with its alkyl group according to the following reaction: RMgX+Sn(NR'2)4→ RSn(NR'2)3+By-product (2) wherein R and R' are as defined above. Similarly, tin tetracarboxylates and tin tetraalkoxides can also be used as reactants to form monoalkyltin carboxylates and monoalkyltin alkoxides, respectively, according to the following reactions: RMgX + Sn(R'COO)4 → RSn(R'COO)3 + by-products (3) RMgX + Sn(OR')4 → RSn(OR')3 + by-products (4) RMgX+Sn(CCR')4→ RSn(CCR')3+byproduct (5) where R and R' are defined above. In some embodiments, the Grignard reagent can be added in approximately a 1:1 molar ratio so that the reaction selectively produces monoalkyltin triamides / tricarboxylates / trialkoxides with low polyalkyltin impurities. The above-described synthetic method improves the selectivity and yield of monoalkyltin triamides / tricarboxylates / trialkoxides by suppressing the formation of dialkyltin by-products. The Grignard reagent approach can be particularly useful for forming secondary and tertiary Sn-C bonds, such as branched alkyl R groups. Monoalkyltin triamides containing low levels of polyalkyl impurities can be further processed to form monoalkyltin trialkoxides with low polyalkyl impurity content. These improved synthetic methods are further described in published U.S. Patent Application Publication No. 2019 / 0315781 to Edson et al., entitled "Monoalkyl Tin Compounds With Low Polyalkyl Contamination, Their Compositions and Methods" (hereinafter referred to as the '781 application), which is incorporated herein by reference.

[0041] For direct synthesis using deuterated organic halides, the enriched composition can be synthesized by the following overall reaction: 3HNR'2+3MR''(+M'Z)+SnX2+RX' → RSn(NR'2)3+by-product (6) or 3R'CCH+3MR''(+M'Z)+SnX2+RX' → RSn(CCR')3+by-product (7) where X and X' are independently a halide, and R" is typically a hydrocarbyl group having 10 or fewer carbon atoms. Because R" will be incorporated into the by-product, typically HR", its identity is generally not limited or critical and can be selected based on general availability, low cost, ease of by-product removal, and good reactivity. Some suitable examples of R" are n-butyl and tert-butyl. The R' group provides a substituent for the corresponding hydrolyzable ligand of the reaction product composition. In these reactions, M is typically lithium, although other alkali metals, i.e., sodium, potassium, rubidium, and cesium, can be substituted for lithium. The parenthesized M'Z represents the optional reactant M"OR" or M'"X2, where M" is an alkali metal ion, OR" is a passive alkoxide, and M'" is an alkaline earth / pseudo-alkaline earth metal ion that, together with the halide ion, X, provides a halide. The Rx compound is selected to provide the desired organotin ligand for the mono-organotin reaction product. As described in the Examples below and the preceding discussion, specific examples of R include deuterated hydrocarbons, such as -CD3(d3-methyl), -C(CD3)3,(d9-tBu), and -CD(CD3)2(d7-iPr). The wide availability of Rx compounds as reactants, as well as their broad reactivity in the corresponding reactions, offers the potential for incorporating a wide variety of organotin ligands into the mono-organotin reaction product. These reactions are further described in co-pending U.S. patent application Ser. No. 17 / 410,316 (Edson et al., entitled "Methods To Produce Organotin Compositions With Convenient Ligand Providing Reactants"), which is incorporated herein by reference.

[0042] To date, the isolation of alkali metal tin triamides or alkali metal tin triacetylides has not been achieved. These improved synthetic methods are unambiguous in terms of the precise identities of the intermediates; the general discussion herein focuses on the overall starting materials and the final reaction products, which can be isolated and identified. Nevertheless, the assumed identities of intermediates, such as KSn(TMSA)3, are based on strong assumptions according to the species present. It is assumed that the metal ions are not fully solvated in the particular solvents used. Nevertheless, the compositions remain in solution, and the formation of large clusters and gelation are not observed. While not wishing to be bound by theory, organometallic reactants, such as alkyllithiums, alkylmagnesiums (Grignard reagents), and potassium tert-butoxide, are known to form metal-metal bonded clusters, such as tetramers, hexamers, and cubanes, and therefore it is plausible that similar species are formed in solution, possibly as complex equilibrium mixtures, which currently defy identification. The relative stabilities of known species suggest what intermediate species might be expected to exist, but precise structural characterization is not necessary to understand their fundamental chemical participation in the reaction. The reactivity of the species would be consistent with the inability to remove the solvent to isolate them.

[0043] Although the general reactions are shown above, these reactions can be carried out in multiple steps. Because one of the reactants is a tin dihalide, such as tin dichloride, considerations for solvent selection should include appropriate solubility for the tin dihalide. Other starting reactants, such as dihydrocarbylamine and monoalkyllithium (or generally, monoalkylalkali metal), may be soluble in different solvents. In some embodiments, if the reactants are sparingly soluble, they can be initially formed into a slurry. The reactions are generally carried out in anhydrous organic solvents under an oxygen-free or oxygen-depleted atmosphere, such as a nitrogen-purged atmosphere, argon, or other inert atmosphere. The solvent is selected to ensure that the various components remain in solution. Because of interactions between the solvent and the metal ion, the selection of the solvent should be based, at least in part, on the reaction rate in the selected solvent, which can be evaluated experimentally. When different solvents are selected, they are generally miscible. Generally, aprotic polar solvents such as ethers (e.g., dimethyl ether, diethyl ether), tetrahydrofuran (THF), acetone, and mixtures thereof are useful. The solvent should generally be selected to be inert to the reactants, intermediates, and reaction products. For example, if multiple solvents are used to introduce individual reactants, the solvents should generally be mutually miscible. The first reaction is believed to be the synthesis of the MSnL3 intermediate, where L is a dialkylamide (dihydrocarbylamide) or alkylacetylide (hydrocarbylacetylide), although no specific structure has been established. Given the reactants and reaction conditions, circumstantial evidence suggests the formation of a tin-ligand bond, and therefore the presence of the residue SnL3, and the metal cation is also likely associated with the tin residue for stabilization, although specific structures may exist in the complex equilibrium mixture.This first reaction can be considered, if desired, as two separate reactions: a first subreaction (MR+HL → ML+HR) to produce the metal-ligand composition (ML), followed by a subreaction with SnCl or other tin dihalides (3ML(+M'OR') + SnX → (MSnL3) + by-products, where M'OP' is an optional component and the structure of MSnL3 has not yet been formally determined). As detailed above, M can be an alkali metal, as well as an alkaline earth metal and / or a pseudo-alkaline earth metal. Typically, in the first reaction, the solution is cooled to below 10°C in some embodiments, and 0°C in further embodiments (which is a convenient temperature for using an ice bath), although temperatures around this range are acceptable for non-aqueous solutions. Cooling to lower temperatures is possible, but need not be maintained at that temperature for the entire reaction time. Cooling allows for desirable control of the reaction while maintaining a reasonable reaction rate. The first sub-reaction can be carried out for any practically acceptable length of time, without any particular limitation. The first sub-reaction can last for at least about 30 seconds, in other embodiments at least about 2 minutes, in some embodiments from 1 minute to 5 hours, and in some embodiments from about 2 minutes to about 3 hours. In some embodiments, the two sub-reactions can be combined and proceed essentially as a single reaction, which essentially means zero time for the first sub-reaction or a short time for the first sub-reaction. When a non-lithium alkali metal alkoxide and / or alkaline earth (or pseudo-alkaline earth) dihalide is introduced as a reactant, the compound can conceptually be added as part of the first sub-reaction or the second sub-reaction, or perhaps in the context of a third sub-reaction between the first and second sub-reactions. As one of ordinary skill in the art will recognize, additional ranges of times and temperatures within the explicit ranges above are contemplated and are within the present disclosure.

[0044] Generally, the alkyl alkali metal (e.g., lithium) reactant and the amine / acetylene reactant are present in approximately stoichiometric amounts, although a small to moderate excess of the amine / acetylene reactant is typically used, e.g., about 1 mole percent (mol%) to about 50 mol% of the amine / acetylene reactant. When non-lithium alkyl alkali metal compounds are used, similar stoichiometric amounts of the ligand precursor (dialkylamine or alkylacetylene) can be used. Generally, a 3:1 ratio of ML composition to the molar amount of Sn is desired for adding three ligands to each tin. When an alkoxyalkali metal compound of a non-lithium metal is used in parallel with an alkyllithium, the alkyllithium can be present in an amount based on the molar equivalents in the amine / acetylene reactant, while the non-alkali metal compound can be present in an equimolar amount relative to the added tin compound. However, if desired, larger amounts of the metal (alkali metal, alkaline earth metal, or pseudo-alkaline earth metal) can be used as long as additional amounts of ML are not produced. In a corresponding embodiment, the tin reactant is added to the ML ligand-donating reactant in approximately equimolar amounts (1:3) so that three ligand-tin bonds are formed at each tin atom. The low amount of impurities from tin by-products with one, two, or four ligands demonstrates the effectiveness of controlling the molar ratio of tin to ML reactant. The metal concentration in the reactant solution is typically from about 0.025 M to about 2 M, and in further embodiments, from about 0.5 to about 1.5 M. A person of ordinary skill in the art will readily recognize that concentration ranges and permissible stoichiometric ratios within the explicit ranges above are contemplated and are within the present disclosure.

[0045] The second reaction involves the introduction of a carbon-tin bond accompanied by the formation of an organoligand bonded to the tin. Conceptually, the carbon-tin bond replaces a metal-tin bond, but the metal is an alkali metal, alkaline earth metal, and / or pseudo-alkaline earth metal. The organoligand bonded to the tin results from the reaction with an organic halide, RX. To form the carbon-tin bond, typically at least a near-stoichiometric amount of organic halide is introduced, although an excess of organic halide is also possible. In some embodiments, a three-fold molar excess of organic halide can be used in the reaction, while in further embodiments, about 1 to about 2 molar equivalents of RX per mole of Sn can be used. The solvent can be the same as that used in the first reaction or can be selected from similarly available solvents and mixtures thereof. The reaction product of the first reaction is generally not purified before carrying out the second reaction, although by-products can be removed as needed. The metal concentration will generally be similar to that in the first reaction step, but will usually be slightly lower due to dilution. To address the exothermic nature of the reaction, the second reaction is generally (but not necessarily) initiated at a lower temperature, such as about 0°C, or more typically about -78.5°C to about 10°C, although in some embodiments, the reactants can be combined at room temperature. After combining the reactants for the second reaction, the reaction can be allowed to continue at the same temperature or allowed to gradually warm to about 20°C to about 50°C, or room temperature (20-24°C). The reaction can proceed for at least about 15 minutes, in some embodiments from about 15 minutes to about 24 hours, and in some embodiments from about 30 minutes to about 15 hours, although longer reaction times can be used if desired. As one of ordinary skill in the art will recognize, additional ranges of concentrations, molar ratios, temperatures, and times for the second reaction are contemplated and are within the present disclosure.

[0046] Due to the exothermic nature of the reactions described herein, it may be advantageous to modify various synthesis parameters, such as the amount of reactants, reaction temperature, reactant addition times, and reaction time. Such considerations are well known to those skilled in the art. A useful analytical method for analyzing reactions and providing operators with information about suitable process conditions is reaction calorimetry. Calorimetric data can provide useful thermodynamic variables for a given reaction. Specifically, scale-dependent variables (e.g., enthalpy heat) can be measured for a desired reaction and used to properly conduct the reaction on a larger scale. In this way, process variables can be properly controlled for reactions of different scales. Reaction calorimetry data is also included in some of the examples in the '316 application. Using the guidelines presented above, combined with the guidance of the examples below, those skilled in the art will recognize that specific parameters for a particular reaction can be adjusted to achieve the desired results. Optimization using routine experimentation can be performed by those skilled in the art over a wide range of product compositions based on these teachings. The exemplified reactions provide good yields and high specificity in the composition of the reaction products.

[0047] The resulting organotin tri(dihydrocarbylamide / hydrocarbyl acetylide) reaction product can be purified. Purification depends on the properties of the reaction product, but generally involves separating the desired reaction product from by-products and potentially any unreacted reactants. Purification can also include removing volatile compounds, including solvents, from the reaction product mixture by drying or exposure to vacuum. For reaction products with significant vapor pressure, it is desirable to purify the reaction product via vacuum distillation or, if desired, fractional distillation designed to achieve high purity. See U.S. Patent Application Publication No. 2020 / 0241413 (Clark et al., entitled "Monoalkyl Tin Trialkoxides and / or Monoalkyl Tin Triamides With Low Metal Contamination and / or Particulate Contamination and Corresponding Methods"), incorporated herein by reference.

[0048] The reaction products, whether previously purified or not, can be further reacted to form derivatives, such as organotin trialkoxides, which can be further purified by the methods described above or other means known in the art. After the trialkoxide composition is prepared, further purification of the composition can be carried out, if desired. In some embodiments, fractional distillation techniques can be used, such as those described in U.S. Pat. No. 10,787,466 (Edson et al., entitled "Monoalkyl tin compounds with low polyalkyl contamination, their compositions and methods"), which is incorporated herein by reference.

[0049] In some embodiments, the hydrolyzable ligand of the photopatternable precursor composition is an alkoxide. Alkoxides are particularly suitable as hydrolyzable ligands for the processing of oxide hydroxide coatings, either solution or vapor processing, due to their storage properties, hydrolysis susceptibility, and relatively mild hydrolysis reaction products, e.g., alcohols, as well as vapor pressures for vapor deposition. Conversion of organotin amides and acetylides to organotin alkoxides can generally be achieved via alcoholysis, represented by the following reaction: RSn(NR'2)3 + 3R''OH → RSn(OR'')3 + 3HNR'2, or RSn(CCR')3+3R''OH → RSn(OR'')3+3HCCR' wherein R′ and R″ are the same or different and are generally alkyl groups having up to 10 carbon atoms. Particularly preferred R′ and R″ groups are methyl, ethyl, propyl, butyl, pentyl (amyl), and, where applicable, their respective isomers, such as tert-amyl.

[0050] In some embodiments, the photosensitive composition is diluted in a solvent to form an improved photoresist solution. Suitable solvents, of course, must include those in which the improved photosensitive composition is suitably soluble, but may be selected based on their physical properties, such as flammability, viscosity, toxicity, and volatility. Other considerations for suitable solvents may include cost and potential interactions with other processing aids. Some examples of suitable solvents include alcohols (e.g., 4-methyl-2-pentanol, 1-butanol, cyclohexanol), esters (e.g., ethyl acetate, propylene glycol monomethyl ether acetate, ethyl lactate), ethers (e.g., propylene glycol monomethyl ether), ketones (e.g., 2-heptanone, cyclopentanone, cyclohexanone, 1-butanone, 4-methyl-2-pentanone), mixtures thereof, and the like. Suitable solvents not explicitly listed herein are contemplated, as would be well understood by one of ordinary skill in the art. The improved photoresist solutions can be used to form radiation-patternable coatings, as described below.

[0051] In some embodiments, the heavy atom-enriched photosensitive composition can be partially or fully hydrolyzed prior to dissolving in a suitable solvent, such as those described above. In such a hydrolyzed composition, the hydrolyzable ligands of the heavy atom-enriched photosensitive composition are partially or fully replaced by O or OH ligands in condensed clusters containing Sn—C bonds and Sn—O and / or Sn—OH bonds.

[0052] In some embodiments, the deuterium-enriched photosensitive composition is a blend solution containing one or more monoalkyltin compounds containing different R groups, and / or other organotin compositions, such as R n SnL 4-n(where n is 2, 3, or 4, and R is as defined above) and their hydrolyzates. Such blend solutions can be adjusted for optimization based on various performance considerations, such as solution stability, coating uniformity, and patterning performance. Blended compositions can be prepared by blending two or more organotin compositions, such as R n SnL 4-n (where L is a hydrolyzable ligand) can be obtained by combing with or without a solvent. For example, neat RSnL3 can be combined with neat R'SnL3 to form a blended precursor. Optionally, the blended composition can then be diluted into a solvent. Alternatively, each individual organotin composition can be diluted in a desired solvent to form an individual organotin solution, and then the individual organotin solutions can be combined to form the blended solution. Generally, the hydrolyzable ligands can be the same or different for each organotin component in the overall blended composition. In some embodiments, the deuterium-enriched photosensitive composition can include at least 1 mol % Sn in the blended solution, in further embodiments at least 10 mol % Sn of the blended solution, in further embodiments at least 25 mol % Sn of the blended solution, and in further embodiments at least 75 mol % Sn of the blended solution. Additional ranges of mol% of the heavy atom-enriched photosensitive composition within the stated range of the blend solution are contemplated and are within the present disclosure. In other embodiments, all of the tin compounds in the precursor solution, e.g., the blend, are deuterated, including a single composition or a blend of multiple deuterated components.

[0053] The natural abundance of deuterium is about 0.016% of hydrogen. Therefore, deuterium enrichment refers to greater than natural abundance, and enrichment can involve replacing a majority of hydrogen with deuterium, e.g., greater than 99% deuterium enrichment. Furthermore, deuteration can involve all of the hydrogen in the (perdeuterated) ligand, or the deuteration can be site-specific. Highly perdeuterated enrichment (greater than 99 mole%) is desirable to increase the effectiveness of deuteration, while lower amounts of deuteration can result in either site-specific or less deuteration. Generally, the degree of deuteration is at least about 50 mole% for site-specific or perdeuteration. As those skilled in the art will appreciate, depending on the composition of the ligand, certain considerations may be taken into account during handling, processing, and storage. 1 From H 2 Exchange to H or vice versa can occur as well. For example, hydrolysis of RSnL3 compositions can produce both Sn-OD and Sn-OH bonds. For purposes of this disclosure, deuteration of the hydrolyzed reaction products is expected and within the scope of this disclosure.

[0054] Radiation-patternable coatings Radiation-patternable coatings can be formed by deposition and subsequent processing of the photosensitive composition onto a selected substrate. Deposition of radiation-patternable coatings can be accomplished by a variety of means known to those skilled in the art.

[0055] Deposition of radiation-sensitive organotin compositions into radiation-patternable coatings is generally achieved via a hydrolysis and condensation process. For example, solution-based deposition of radiation-patternable organotin coatings is described in the Meyers reference cited above. Vapor deposition methods employing hydrolysis / condensation-based reactions have also been described in published PCT patent WO 2019 / 217749 (Wu et al., entitled "Methods for Making EUV Patternable Hard Masks") (incorporated by reference), as well as the previously cited '618 patent. In either case, the radiation-sensitive organotin composition can be significantly converted to an organotin hydroxide oxide, in which radiation-sensitive organic ligands having Sn-C bonds to the Sn atoms are incorporated into a loosely connected network of Sn-O-Sn and Sn-OH bonds. Due to the incorporated organic ligands, the resulting coatings can be considered hydrophobic.

[0056] If solution deposition is desired, a particularly useful solution deposition method is spin coating. Spin coating is well known in the art and can be particularly useful in photoresist processing in semiconductor fabrication. In a typical spin coating process, a photoresist solution is delivered to the surface of a substrate, such as a Si wafer, and the substrate is spun at high speed to form a coating. During the spin coating process, the hydrolyzable ligands of the organotin composition react with ambient moisture, undergoing significant hydrolysis and condensation to form a coating on the substrate that contains Sn-O-Sn and Sn-OH networks along with radiation-sensitive Sn-C bonds. In some embodiments, the improved photoresist solution is spin-applied at a spin speed between 500 and 3000 rpm. There is no particular limit to the rpm used, but it is generally adjusted to obtain the desired coating thickness. Generally, for a given photoresist solution, slower spin speeds result in thicker coatings than faster spin speeds. Those skilled in the art will understand the relationship between spin speed and coating thickness.

[0057] The thickness of the coating can also depend on the concentration of Sn in the photoresist solution. In some embodiments, the [Sn] concentration in a suitable solvent is from 0.005 to about 1.0 M, in further embodiments from about 0.01 M to about 0.5 M, and in further embodiments from about 0.05 M to about 0.1 M. As will be appreciated by those of ordinary skill in the art, additional ranges of [Sn] concentrations are contemplated and are within the present disclosure.

[0058] The thickness of the radiation-patternable coating can depend on the process desired. For use in single-patterning EUV lithography, the coating thickness is generally selected to provide a pattern with few defects and good pattern reproducibility. In some embodiments, a suitable coating thickness is between 0.5 nm and 100 nm, in further embodiments, about 1 nm to 50 nm, and in further embodiments, about 2 nm to 25 nm. As will be appreciated by those skilled in the art, additional ranges of coating thickness are contemplated and are within the present disclosure.

[0059] In other embodiments, the radiation-patternable coatings can be formed via various vapor deposition methods, such as atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etc. Typical vapor-phase deposition methods generally involve reacting one or more metal-containing precursors with one or more small molecule vapor-phase reactants, such as HO, HO, O, O, or CHOH, which serve as O and H sources to produce oxides and oxide hydroxides. Thus, hydrolyzable compounds can be directly deposited by vapor-phase hydrolysis to form the corresponding alkyltin oxide hydroxide coatings, which can then be appropriately patterned.

[0060] In CVD processes, two or more reactant gases are typically mixed in a chamber near the substrate surface. Therefore, sufficient stability is designed into the reaction conditions to control undesired gas-phase reactions and nucleation. ALD precursors, introduced separately and sequentially into the reaction chamber, typically react with chemisorbed co-precursors or decomposition reaction products that saturate the substrate surface. Desirable characteristics of RSnL3 precursors include, for example, sufficient volatility for vapor transport into the system, thermal stability to prevent premature decomposition, and appropriate reactivity with co-precursors to produce the desired reaction products under given process conditions. The pressure and temperature in the reaction chamber can be selected to control the reaction process.

[0061] For radiation-patternable coatings prepared by vapor deposition, the coating thickness can generally be controlled by appropriately selecting the reaction time or number of cycles of the process. The thickness of the radiation-patternable coating can depend on the desired process. For use in single-patterning EUV lithography, the coating thickness is generally selected to provide a pattern with few defects and good pattern reproducibility. In some embodiments, suitable coating thicknesses are between 0.5 nm and 100 nm, in further embodiments, about 1 nm to 50 nm, and in further embodiments, about 2 nm to 25 nm. As will be appreciated by those skilled in the art, additional ranges of coating thickness are contemplated and are within the present disclosure.

[0062] The substrate generally provides a surface onto which a coating material can be deposited, and may be comprised of multiple layers, of which the surface refers to the top layer. The substrate is not particularly limited and may include any suitable material, such as silicon, silica, other inorganic materials, e.g., ceramics, and polymeric materials.

[0063] After deposition to form a radiation-patternable coating, further processing can be employed prior to exposure to radiation. In some embodiments, the coating can be heated between 30°C and 300°C, in further embodiments between 50°C and 200°C, and in further embodiments between 80°C and 150°C. The heating can be carried out in some embodiments for about 10 seconds to about 10 minutes, in further embodiments for about 30 seconds to about 5 minutes, and in further embodiments for about 45 seconds to about 2 minutes. Additional ranges of temperatures and heating times within the explicit ranges above are contemplated and envisioned.

[0064] Patterning of the composition: The radiation can generally be applied directly to the coated substrate through a mask, or the radiation beam can be scanned over the substrate in an adjustable manner. The radiation can generally include electromagnetic radiation, electron beams (beta rays), or other suitable radiation. The electromagnetic radiation can generally have a desired wavelength or wavelength range, such as visible light, ultraviolet light, or X-rays. The achievable resolution of a radiation pattern generally depends on the wavelength of the radiation, and generally, higher resolution patterns can be obtained using radiation with shorter wavelengths. Therefore, to obtain particularly high resolution patterns, it is desirable to use ultraviolet light, X-rays, or electron beams.

[0065] According to the international standard ISO 21348 (2007) (incorporated herein by reference), ultraviolet light refers to wavelengths between 100 nm and less than 400 nm. Krypton fluoride lasers can be used as a source of 248 nm ultraviolet light. The ultraviolet range can be further subdivided in several ways in accepted standards, such as extreme ultraviolet (EUV) from 10 nm to less than 121 nm, and far ultraviolet (FUV) from 122 nm to less than 200 nm. The 193 nm line from an argon fluoride laser can be used as a radiation source for FUV. 13.5 nm EUV light has been used for lithography, but this light is generated by Xe or Sn plasma sources excited using high-energy lasers or discharge pulses. Soft x-rays can be defined as from 0.1 nm to less than 10 nm.

[0066] The amount of electromagnetic radiation can be characterized by fluence or dose, which is given by the integrated radiant flux over the exposure time. In some embodiments, a suitable radiation fluence is about 1 mJ / cm. 2 ~about 200mJ / cm 2 and in further embodiments, about 2 mJ / cm 2 ~Approx. 150mJ / cm 2 and in further embodiments, about 3 mJ / cm 2 ~about 100mJ / cm 2 In one embodiment, the EUV irradiation can be about 150 mJ / cm 2 At a dose of less than 2 mC / cm or at 30 kV, 2 This can be accomplished with an electron beam at a dose no greater than that. A person of ordinary skill in the art will recognize that additional ranges of radiation fluence within the explicit ranges above are contemplated and are within the present disclosure.

[0067] During exposure to radiation, such as ultraviolet (UV), extreme ultraviolet (EUV), and electron beam, and subsequent processing, the Sn-C and / or Sn-carboxylate bonds dissociate to form a denser, more hydrophilic oxide-hydroxide network. As the relative concentration of organic ligands in the exposed regions decreases, the exposed regions become more polar and the exposed regions become more hydrophilic.

[0068] Depending on the design of the coating material, a large contrast in material properties can be achieved between the irradiated regions (where the coating material is condensed) and the unirradiated regions (where the Sn—C bonds remain substantially unchanged). In embodiments employing a post-irradiation heat treatment, the post-irradiation heat treatment can be carried out at temperatures ranging from about 45°C to about 250°C, from about 50°C to about 190°C in further embodiments, and from about 60°C to about 175°C in further embodiments. Post-exposure heating can generally be carried out for at least about 0.1 minutes, from about 0.5 minutes to about 30 minutes in further embodiments, and from about 0.75 minutes to about 10 minutes in further embodiments. Those skilled in the art will recognize that additional ranges of post-irradiation heating temperatures and times within the ranges specified above are contemplated and are within the present disclosure. This high contrast in the material facilitates the formation of high-resolution lines with smooth edges in the pattern, as discussed in the next section.

[0069] For negative-tone imaging, the developer can be an organic solvent, such as the solvent used to form the precursor solution. The choice of developer is generally influenced by factors such as the solubility parameters for both irradiated and unirradiated coating materials, as well as the developer's volatility, flammability, toxicity, viscosity, and potential chemical interactions with other process materials. Specifically, suitable developers include, for example, alcohols (e.g., 4-methyl-2-pentanol, 1-butanol, isopropanol, 1-propanol, methanol), ethyl lactate, ethers (e.g., tetrahydrofuran, dioxane, anisole), ketones (pentanone, hexanone, 2-heptanone, octanone), and the like. Development can be carried out for about 5 seconds to about 30 minutes, in further embodiments from about 8 seconds to about 15 minutes, and in additional embodiments from about 10 seconds to about 10 minutes. A person of ordinary skill in the art will recognize that additional ranges within the explicit ranges above are contemplated and are within the present disclosure. In addition to the primary developer composition, the developer may contain additional compositions to facilitate the development process. Suitable additives include, for example, viscosity modifiers, solubilization aids, or other processing aids. When optional additives are present, the developer may contain up to about 10 weight percent of the additive, and in further embodiments, up to about 5 weight percent of the additive. As will be appreciated by those skilled in the art, additional ranges of additive concentrations within the above-specified ranges are contemplated and are within the present disclosure. Developer blends and additives are also described in U.S. Patent Application Publication No. 2020 / 0326627 (Jiang et al., entitled "Organometallic Photoresist Developer Compositions and Processing Methods"), which is incorporated herein by reference.

[0070] When using a weaker developer, such as a diluted organic developer, or a composition in which the coating development rate is slow, a higher temperature development process can be used to increase the processing speed. With a stronger developer, the development process temperature can be lowered to reduce the speed and / or adjust the development kinetics. Generally, the development temperature should be adjusted to an appropriate value that matches the volatility of the solvent. Furthermore, developers that dissolve the coating material near the developer-coating interface can be dispersed ultrasonically during development. The developer can be applied to the patterned coating material using various rational approaches. For example, the developer can be sprayed onto the patterned coating material. Spin coating can also be used. In automated processing, a puddle method can be used, in which the developer is poured onto the coating material in a stationary format. If desired, spin rinsing and / or drying can be used to complete the development process. Suitable rinsing solutions include, for example, ultrapure water, aqueous tetraalkylammonium hydroxide, methyl alcohol, ethyl alcohol, propyl alcohol, and combinations thereof. After the image is developed, the coating material is disposed in a pattern on the substrate.

[0071] In some embodiments, a solvent-free (dry) development process can be carried out using a suitable thermal or plasma development process, such as those described in the following published PCT patent: WO 2020 / 264158 (Tan et al., entitled "Photoresist Development With Halide Chemistries"), which is incorporated herein by reference. For organotin photoresist coatings, dry development methods can be carried out using halogen-containing plasmas and gases, such as HBr and BCl. In some cases, dry development methods offer advantages over wet development methods, such as reduced pattern collapse, reduced scum, and precise control of the developer composition, i.e., plasma and / or etch gases.

[0072] After the development step is complete, the coating material can be heat-treated to further condense, dehydrate, densify, or remove residual developer from the material. This heat treatment can be particularly desirable in embodiments in which the oxide coating material will be incorporated into an ultimate device, but it is also desirable in some embodiments in which the coating material will be used as a resist and ultimately removed if stabilization of the coating material is desired to facilitate further patterning. In particular, baking of the patterned coating material can be carried out under conditions such that the patterned coating material exhibits a desired level of etch selectivity. In some embodiments, the patterned coating material can be heated to a temperature of from about 100°C to about 600°C, from about 175°C to about 500°C in further embodiments, and from about 200°C to about 400°C in further embodiments. Heating can be carried out for at least about 1 minute, from about 2 minutes to about 1 hour in other embodiments, and from about 2.5 minutes to about 25 minutes in further embodiments. Heating may be carried out in air, vacuum, or an inert gas atmosphere such as Ar or N. A person of ordinary skill in the art will recognize that additional ranges of temperatures and times for heat treatment within the explicit ranges above are contemplated and are within the present disclosure. Similarly, non-heat treatments, such as blanket UV exposure or exposure to an oxidizing plasma such as O, may also be employed in similar processes.

[0073] In some embodiments, adjacent linear segments of adjacent structures can have an average pitch (half pitch) of about 60 nm or less (30 nm half pitch or less), in some embodiments about 50 nm or less (25 nm half pitch or less), and in further embodiments about 34 nm or less (17 nm half pitch or less). Pitch can be estimated from the design and confirmed using scanning electron microscopy (SEM), for example, top-down imaging. As used herein, pitch refers to the spatial period or center-to-center distance of repeating structural elements, and as commonly used in the art, half pitch is half the pitch. Feature dimensions of a pattern can also be described in terms of the average width of the feature, which is typically estimated from a corner or the like. Additionally, a feature can refer to the gap between and / or to material elements. The average width can be about 25 nm or less in some embodiments, about 20 nm or less in further embodiments, and about 15 nm or less in yet further embodiments. A person of ordinary skill in the art will recognize that additional ranges of pitch and average width within the explicit ranges above are contemplated and are within the present disclosure.

[0074] In some embodiments, the average linewidth roughness can be about 5.5 nm or less, in some embodiments, about 5 nm or less, and in further embodiments, about 4.5 nm or less. This is performed by analyzing top-down SEM images to derive the 3σ deviation from the average linewidth. The average includes high-frequency roughness and low-frequency roughness, i.e., short correlation length and long correlation length, respectively. While the linewidth roughness of organic resists is primarily characterized by long correlation length, the organometallic coating materials of the present invention exhibit significantly shorter correlation lengths. In pattern transfer processes, the short correlation roughness can be smoothed out during the etching process to achieve higher pattern fidelity. As one of ordinary skill in the art will recognize, additional ranges of linewidth roughness within the explicit ranges above are contemplated and are within the present disclosure. Rinsing can be performed to further remove some patterning defects and improve pattern fidelity, as described in U.S. Patent Application Publication No. 2020 / 0124970 (Kocsis et al., entitled "Patterned Organometallic Photoresists and Methods of Patterning"), which is incorporated herein by reference. [Example]

[0075] Example 1: Preparation of nonadeutero-tert-butyltin tris(tert-butoxide) via oxidative stannylation: This example demonstrates the synthesis of deuterated monoalkyltin trialkoxides using an oxidative stannylation reaction to introduce the deuterated ligand as an alkyl halide.

[0076] n-Butyllithium (1.03 mL, 2.53 mmol, 2.45 M in hexane) was added to a cooled (-50°C) solution of diethylamine (0.262 g, 2.53 mmol) in diethyl ether (4 mL). After several minutes, a slurry of tin(II) chloride (0.160 g, 0.845 mmol) and potassium tert-butoxide (0.095 g, 0.845 mmol) in THF (4 mL) was added. The contents were warmed to 0°C and stirred for 2 hours. The flask was recooled to -50°C, and a solution of nonadeuterioiodide-tert-butyl iodide in THF was added dropwise. After stirring for 16 hours, tert-butanol (3.1 equiv.) was added. After 0.25 hours, the solvent was removed in vacuo and pentane was added. After removing the salts by filtration and removing the pentane under vacuum, nonadeutero-tert-butyltin tris(tert-butoxide) was obtained as a colorless liquid. This compound was further purified by fractional distillation to give the product d9-tBuSn(Ot-Bu)3 in C6D6. 2 H, 13 C, and 119 The Sn NMR spectra were measured and are shown in Figures 1A, 1B, and 1C, respectively.

[0077] Example 2: Preparation of nonadeutero-tert-butyltin tris(tert-butoxide) via Grignard reaction: Part 1. Synthesis of d9-t-BuSn(NMe2)3. In an argon-filled glovebox, a 5 L, three-neck, round-bottom flask was charged with Sn(NMe2)4 (827.5 g, 2805 mmol, Sigma). To the flask, dry ether (2000 mL) was added. A predetermined amount of deuterated t-BuMgCl (1500 mL, 2.06 M (freshly titrated), 3090 mmol) was added to a separate 2 L, two-neck, round-bottom flask. The flasks were capped and attached to a Schlenk line. The Sn(NMe2)4 solution was transferred to a 5 L jacketed reactor and stirred at 240 RPM. Using an automated syringe pump, the deuterated t-BuMgCl solution was added to the 5 L jacketed reactor at 50 mL min -1The temperature of the mixture in the jacketed reactor was maintained at 20° C. After complete addition of the d9-t-BuMgCl solution, the reaction was stirred overnight.

[0078] The resulting mixture was passed through a 10 L filter reactor and transferred into a 5 L, 3-neck round-bottom flask equipped with a stir bar. The 5 L jacketed reactor and the solids in the filter reactor were rinsed with pentane (2 x 1 L). The rinses were collected in a 5 L, 3-neck round-bottom flask equipped with a stir bar, and the volatiles were removed under vacuum. Once the volatiles were removed, a pale yellow oily suspension was observed, corresponding to the crude reaction product. The flask was brought into a glove box, and the crude reaction product was filtered through a coarse fritted funnel. The filtrate was transferred into a 2 L, 2-neck round-bottom flask equipped with a stir bar, stoppered, and transferred to a Schlenk line. The crude reaction product was purified by short-path vacuum distillation (500 mTorr, 65°C-75°C) into a 1 L receiver flask to give 323-604 g, 37-70%, of a colorless oil identified as d9-t-BuSn(NMe2)3.

[0079] Part 2. Synthesis of d9-t-BuSn(Ot-Bu) from d9-t-BuSn(NMe2)3. In a glovebox, a 2-L, two-neck RBF was charged with approximately 500 mL of pentane and d9-t-BuSn(NMe2)3 (329.4 g, 1.07 mol) from Part 1. The flask was tared on a balance, and tris(2-aminoethyl)amine (3.91 g, 26.7 mmol) was added directly to the reaction mixture via syringe. A magnetic stir bar was added, and the reaction was sealed and connected to a Schlenk line. The flask was cooled in a dry ice / isopropanol bath. A separate 1-L Schlenk flask was charged with tert-butanol (292.2 g, 3.315 mol) and a small amount of pentane and connected to a Schlenk line. The alcohol / pentane solution in the Schlenk flask was transferred via cannula to a reaction flask equipped with an outlet purge to a mineral oil bubbler plumbed to an acid trap solution for NMeH produced as an off-gas. After the alcohol addition was complete, the reaction was allowed to warm to room temperature and stirred for 1 hour. After the 1-hour reaction time, the solvent was removed in vacuo, and the reaction product was vacuum distilled (95-97 °C, 500 mtorr) to give 435 g (93%) of a colorless oil.

[0080] Example 3: Preparation of trideuterated methyltin tris(phenylacetylide) and trideuterated methyltin tris(tert-pentoxide): This example demonstrates the synthesis of deuterated tin tris(phenylacetylide) and the corresponding trialkoxide.

[0081] n-Butyllithium (300 mmol / 1.6 M in hexane) was added to a cold (-78 °C) solution of diethylamine (350 mmol) in diethyl ether (500 mL). After a few minutes, tin(II) chloride (100 mmol in 100 mL of tetrahydrofuran) was added dropwise. The contents were warmed to room temperature and stirred for 2 hours. The flask was recooled to -78 °C, and trideuterated iodomethane (120 mmol) was added. The resulting reaction mixture was allowed to warm to room temperature over 16 hours, at which point the solvent was removed in vacuo. The contents were redissolved in diethyl ether and filtered over a silica plug. Volatiles were then removed to give the crude reaction product (a low-melting solid), d3-MeSn(CCPh)3. The reaction product in C6D6 2 H and 119 NMR spectra were measured and are shown in Figures 2A and 2B, respectively.

[0082] The crude reaction product, d3-MeSn(CCPh)3, was dissolved in 2-methyl-2-butanol (100 mL) and heated for 1 week while an aliquot was monitored by NMR. The volatiles were removed, but conversion was found to be insufficient, so additional 2-methyl-2-butanol (100 mL) was added and the reaction continued for another week. The volatiles were removed, but conversion was still found to be insufficient, so additional 2-methyl-2-butanol (300 mL) was added and the reaction continued for another week. After removal of the volatiles, the d3-MeSn(t-pentoxide)3 reaction product was fractionally distilled to give a clear oil. The reaction product was analyzed in C6D6. 119 Sn and 1 1 H NMR was measured and the spectra are shown in Figures 3A and 3B, respectively.

[0083] Example 4: EUV patterning of nonadeuterated-tert-butyltin tris(tert-butoxide): The nonadeuterated tert-butyltin tris(tert-butoxide) material prepared according to Example 1 was dissolved in an appropriate amount of 4-methyl-2-pentanol to form a 0.05 M [Sn] solution, followed by deposition by spin-coating as previously described.

[0084] A series of films were deposited onto SOG-coated silicon wafers with a film thickness of 23.4±0.8 nm. The films were exposed using an NXE3400C EUV scanner employing a mask designed to print a 16P32 (16 nm linewidth, 32 nm pitch) pattern. The exposed films were baked at various temperatures and then developed using a developer of PGME + 5% acetic acid. After development, the films were baked at 250°C for 60 seconds to remove developer residue.

[0085] The resulting patterns were imaged using a Hitachi CG5000 CD-SEM (critical dimension scanning electron microscope) at a beam voltage of 800 V and a beam current of 8.0 pA. Figure 4 summarizes the dose (mJ / cm²), linewidth (CD, nm), and linewidth roughness (LWR, nm) for selected images and each pattern. The headings above each image indicate the post-exposure bake temperature. Each pattern shows the CD closest to the target linewidth (16 nm).

[0086] Example 5: Comparison of deuterated compounds This example compares deuterated compounds prepared according to Example 1 and Example 2.

[0087] Part 1. FTIR Analysis: The nonadeuterated-tert-butyltin tris(tert-butoxide) material prepared according to Example 1 ("D1") was dissolved in an appropriate amount of 4-methyl-2-pentanol to form a 0.05 M [Sn] solution. This was followed by spin-coating deposition to form a series of films ("F1") on SOG-coated silicon wafers. The films were deposited to a film thickness of approximately 28 nm before baking. The nonadeuterated-tert-butyltin tris(tert-butoxide) material prepared according to Example 2 ("D2") was also dissolved in an appropriate amount of 4-methyl-2-pentanol to form a 0.05 M [Sn] solution, which was then spin-coated onto SOG-coated silicon wafers to form a second set of films ("F2"). These films were deposited under the same conditions as for film F1, resulting in a film thickness of approximately 28 nm. Pairs of film samples from F1 and F2 were subjected to selected heating conditions. Since the formation of the coating resulted in substantially complete hydrolysis and removal of the hydrolyzable ligands, they were deemed not to require further analysis.

[0088] After the selected heating conditions were completed, each film was analyzed by FTIR. Figure 5 compares stacked FTIR spectra of film samples F1 and F2, which were subjected to different heating conditions: (A) no bake, (B) 50°C bake, (C) 100°C bake, (D) 150°C bake, (E) 180°C bake, (F) 200°C bake, and (G) 240°C bake. Each bake time was 120 seconds. The CH stretching vibrations, CO absorption vibrations, and CD stretching vibrations are shown in boxes 110, 112, and 114, respectively. Because the FTIR measurements were performed in ambient atmosphere, the CO absorption region was obscured and was ignored in the analysis.

[0089] Spectrum (A) shows that the film sample from F1 exhibited CH absorption peaks, whereas those from F2 were absent. Film samples from F1 and F2 exhibited similar CD absorption peaks. This result suggests the presence of non-deuterated compounds in the D1 material. The non-deuterated compounds are impurities, and they are absent in the D2 material. This suggests that the purity of the material prepared by the Grignard synthesis is higher in terms of organic compounds than that prepared by the oxidative stannylation synthesis. Deuterated materials offer the analytical advantage of improved contrast between reaction products and impurities. Spectrum (B)–(G) shows that the film sample from F1 exhibited less intense CH absorption peaks after heating at 50°C, whereas these peaks were absent in films heated above 100°C. This suggests that the impurities were polymeric compounds that decomposed at high temperatures.

[0090] Part 2. Solubility Contrast with EUV Exposure: Films were deposited on silicon wafers as described in Part 1. Precursor solutions of D1, D2, and non-deuterated tert-butyltin tris(tert-butoxide) (“P1”) were prepared at concentrations suitable for depositing films of D1, D2, and P2, respectively, each approximately 20 nm thick. The non-deuterated compositions were prepared as described in Example 5 of the previously cited '781 application, except that t-amyl alcohol was replaced with t-butyl alcohol. For the contrast curves shown in Figure 6, film thicknesses ranged between 18.3 nm and 18.5 nm.

[0091] The films were exposed at Lawrence Berkeley National Laboratory using an EUV Direct Contrast Tool. The films were baked at 100°C for 2 minutes before exposure. A linear array of 50 circular exposure areas, each approximately 500 μm in diameter, was projected onto the wafer at increasing EUV exposure doses. After exposure, the films were baked at 180°C for 1 minute and then developed using a solution of 5% acetic acid by volume in PGMEA. The thickness of each exposed pad was evaluated using a JAWoollam M-2000 spectroscopic ellipsometer. The thickness of each pad as a function of EUV dose is plotted in Figure 6. Contrast curves 120, 124, and 128 correspond to the P1, D1, and D2 films, respectively. In the unexposed and low-dose regions, the film thickness was approximately 8.6–8.8 nm, which corresponds to the thickness of the SOG coating. The curves rise to a maximum thickness in the range of 18.3 nm to 18.5 nm. The maximum thicknesses of contrast curve 120 (material P1) and contrast curve 128 (material D2) are nearly identical, although contrast curve 128 (material D1) exhibits a slightly lower maximum thickness. Table 1 lists the process conditions, developer compositions, and results obtained for each material (D o , D g , and contrast).

[0092] [Table 1]

[0093] These results indicate that the deuterated materials D1 and D2 have different radiation sensitivities than the non-deuterated materials. D1 and D2 had gel doses approximately 50% higher than that of P1. The slower reaction under comparable processing conditions was an expected result of the heavy atoms. However, D1 and D2 exhibited a solubility contrast comparable to P1. This high contrast in physical properties facilitates the creation of fine lines with smooth edges in patterns, as demonstrated in Example 4. Comparing the two deuterated materials, D2 exhibited a slightly lower gel dose than D1 and also a better solubility contrast than D1. These results suggest that the radiation sensitivity of the deuterated materials is related to the presence of impurities and therefore depends on the synthetic route, as confirmed and explained in the FTIR analysis in Part 1, and that the Grignard method results in a lower D g Improved EUV contrast. The results in Part 1 suggest that the improvement in contrast at D2 is related to the reduction in impurities.

[0094] This example demonstrates the differences between deuterated and non-deuterated organotin materials, which offer analytical advantages over non-deuterated organotin materials and can be used to tune patterning performance.

[0095] Further inventive concepts: A. A method for synthesizing monoorganotin trialkoxides, monoorganotin triacetylides, or monoorganotin tricarboxylates, the method comprising reacting a Grignard alkylating agent RMgX with SnL4, wherein R is a hydrocarbyl group having 1 to 31 carbon atoms, where X is a halogen, and where R' is a hydrocarbyl group having 1 to 10 carbon atoms, and L is R'COO, CCR', or OR', where R' has 1 to 10 carbon atoms and optional heteroatoms, in a solution comprising an organic solvent. A1. The method according to Concept A of the present invention, wherein R comprises at least one deuterium atom. A2. The method according to Concept A of the present invention, wherein R comprises an alkyl, cycloalkyl, alkenyl, alkynyl, or aryl group having at least one hydrogen atom replaced with deuterium. A3. The method according to Concept A or A2 of the present invention, wherein R is perdeuterated. A4. The method of any one of Concepts A-A3 of the present invention, wherein R is attached to the tin at a secondary or tertiary carbon. A5. The method according to Concept A, A1, or A3 of the present invention, wherein R comprises a cyano, thio, ether, keto, ester, halogenated group, or a combination thereof. A6. The method according to any one of Concepts A to A6 of the present invention, wherein R' is methyl or ethyl. A7. The method according to any one of Concepts A-A7 of the present invention, wherein RMgX and Sn(L)4 are in a molar ratio of approximately 1:1.

[0096] The above-described embodiments are intended to be illustrative and not limiting. Additional embodiments exist within the claims. In addition, while the present invention has been described with reference to specific embodiments, those skilled in the art will readily recognize that changes can be made in form and detail without departing from the spirit and scope of the present invention. Any incorporation of the above-referenced documents is limited and does not incorporate any subject matter contrary to the express disclosure herein. To the extent that particular structures, compositions, and / or processes are described herein with reference to components, elements, ingredients, or other partitions, unless otherwise specified, the disclosure herein should be understood to cover, in certain embodiments, embodiments that include the particular components, elements, ingredients, other partitions, or combinations thereof, as well as embodiments that consist essentially of such particular components, elements, ingredients, other partitions, or combinations thereof, including additional features that do not alter the basic essence of the subject matter as suggested in the description.

Claims

1. An organotin compound represented by the formula RSnL ３ wherein R is a deuterated hydrocarbyl group and L is a hydrolyzable ligand.

2. The organotin compound according to claim 1, wherein R contains an alkyl, cycloalkyl, alkenyl, alkynyl, or aryl group having at least one hydrogen atom substituted with deuterium.

3. The organotin compound according to claim 1, wherein R contains a perdeuterated group containing alkyl, cycloalkyl, alkenyl, alkynyl, or aryl.

4. The organotin compound according to claim 1, wherein R contains a branched alkyl group.

5. The organotin compound according to claim 1, wherein R contains cyano, thio, ether, keto, ester, halogenated group, or a combination thereof.

6. The organotin compound according to claim 1, wherein R is (CD ３ ) ３ C-.

7. The organotin compound according to claim 1, wherein R is CD ３ -.

8. The organotin compound according to claim 1, wherein R is (CD ３ ) ２ CD-.

9. The organotin compound according to claim 1, wherein L is -NR' ２ , -OR', -R'COO － , -CC(R'), -CC(SiR' ３ ) (wherein R' is a hydrocarbyl group having 30 or fewer carbon atoms).

10. The organotin compound according to claim 1, wherein L is -NMe ２ , -NEt ２, -OiPr, -OtBu, -Ot amyl, -CC(Si(CH ３ )) ３ ), -CC(C ６ H ５ ), or a combination thereof, the organotin compound according to claim 1.

11. The organotin compound according to claim 1, wherein the organotin compound is perdeuterated.

12. The organotin compound according to claim 1, wherein the organotin compound comprises nonadeuterated -tert-butylstannyltris(tert-butoxide), trideuterated methylstannyltris(phenylacetylide), or trideuterated methylstannyltris(tert-pentoxide).

13. A precursor solution comprising an organic solvent and the organotin compound according to any one of claims 1 to 12.

14. Formula R ｎ SnX ４－ｎ (wherein n is 2, 3, or 4, R is a hydrocarbyl group, and X is a hydrolyzable ligand), the precursor solution according to claim 13, further comprising one or more organotin compositions.

15. The organic solvent comprises an alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester, an ether, a ketone, or a combination thereof, and the solution has a concentration of about 0.005 M to about 1.4 M based on the concentration of tin, the precursor solution according to claim 13.

16. The organic solvent comprises 4-methyl-2-pentanol, the precursor solution according to claim 13.

17. A method for synthesizing a deuterated organotin composition, the method comprising forming a primary halide hydrocarbyl compound (R-X, where X is a halide atom) with a metal cation M to form an alkali metal tin composition in SnL ３An organometallic composition containing a residue, where M is an alkali metal, an alkaline earth metal, and / or a pseudo-alkaline earth metal (Zn, Cd, or Hg), and L is either an amide ligand that gives an alkali metal stannamide compound or an acetylide ligand that gives an alkali metal stannatriacetylide, is reacted to form the corresponding monohydrocarbylstannamide (RSn(NR' ２ )) ３ or monohydrocarbylstannatriacetylide (RSn(C≡CR ｓ )) ３ ), where the monohydrocarbyl ligand (R) is a deuterated hydrocarbyl group having 1 to 31 carbon atoms and optional unsaturated carbon-carbon bonds, optional aromatic groups, and optional heteroatoms, and R ｓ is either SiR'' ３ or R', where the three R'' are independently H or R', and the R' is independently a hydrocarbyl group having 1 to 31 carbon atoms and optional unsaturated carbon-carbon bonds, optional aromatic groups, and optional heteroatoms. **Claim 18** To form the alkali metal tin composition, in an organic solvent, M'L, tin(II) halide (SnX ２ , X = F, Cl, B, I, or a mixture thereof), and optionally M''OR ０ [where M' is Li, Na, K, Cs, or a combination thereof, M'' is Na, K, Cs, or a combination thereof, and L is a dialkylamide (-NR' ２ )) or an acetylide (-C≡CL ｓ ))] are reacted to form an organometallic composition having the corresponding residue SnL ３ , which is a stannamide (MSn(NR' ２ )) ３ or stannatriacetylide (MSn(C≡CL ｓ )) ３ accompanied by the metal cation M, where M is M'' if M'' is present or M' if M'' is not present, and L ｓ is SiR’’ ３ or R’, where three R’’s are independently H or R’, and R ０ and R’ are independently hydrocarbyl groups having from 1 to 31 carbon atoms and optional unsaturated carbon-carbon bonds, optional aromatic groups, and optional heteroatoms, by a method comprising synthesizing an organometallic composition comprising an SnL ３ residue with a metal cation M, the method of claim 17. **Claim 19** ML is synthesized by a method comprising reacting a monoalkyl alkali metal with a dihydrocarbylamine (HNR’ ２ ), or a hydrocarbyl acetylide (HC≡CL ｓ ), the method of claim 18. **Claim 20** The organometallic composition comprising an SnL ３ residue with a metal cation M is used without purification, the method according to any one of claims 17 to 19. **Claim 21** The reaction of RX with the organometallic composition comprising an SnL ３ residue with a metal cation M comprises reacting at a temperature of about -78.5 °C to about 10 °C, the method according to any one of claims 17 to 19. **Claim 22** M = Li, and the primary halide hydrocarbyl compound and the organometallic composition comprising an SnL ３ residue with a metal cation M are supplied in a molar ratio of about 1:1 to about 3:1, the method according to any one of claims 17 to 19. **Claim 23** The method according to any one of claims 17 to 19, further comprising reacting the deuterated organotin composition with an alcohol to form a deuterated monohydrocarbyltin trialkoxide. **Claim 24** The method of claim 23, wherein the deuterated organotin composition is not purified before reacting with the alcohol. Claim 25 The method according to any one of claims 17 to 19, wherein R is deuterated. Claim 26 The method according to any one of claims 17 to 19, comprising an alkyl, cycloalkyl, alkenyl, alkynyl, or aryl group having at least one hydrogen atom substituted with deuterium in R. Claim 27 The method according to any one of claims 17 to 19, wherein R contains a branched alkyl group. Claim 28 The method according to any one of claims 17 to 19, wherein R contains cyano, thio, ether, keto, ester, halogenated group, or a combination thereof. Claim 29 A method for synthesizing a deuterated monoorganotin triamide compound, the method comprising reacting RMgX of a Grignard alkylating agent with Sn(NR' ２ ) ４ (wherein R is a hydrocarbyl group having 1 to 31 carbon atoms and at least one deuterium atom, and wherein X is a halogen, and wherein R' is a hydrocarbyl group having 1 to 10 carbon atoms) in a solution containing an organic solvent. Claim 30 The method according to claim 29, comprising an alkyl, cycloalkyl, alkenyl, alkynyl, or aryl group having at least one hydrogen atom substituted with deuterium in R. Claim 31 The method according to claim 29 or claim 30, wherein R is deuterated. Claim 32 The method according to claim 29, wherein R contains a branched alkyl group. Claim 33 The method according to claim 29, wherein R contains cyano, thio, ether, keto, ester, halogenated group, or a combination thereof. Claim 34 The method according to claim 29 or claim 30, wherein R' is methyl or ethyl.

35. RMgX and Sn(NR' ２ ) ４ The method according to claim 29 or claim 30, wherein they are in a molar ratio of approximately 1:1.

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