The present invention provides a process for producing monooctyltin trichloride comprising very low levels of dioctyltin and trioctyltin compounds, said process comprising the following steps: (1) Contacting an organotin chloride mixture comprising monooctyltin chloride with an aqueous phase containing halide ions, said step optionally being carried out in the presence of organic solvent; (2) separating the resulting aqueous phase which is rich in monooctyltin chloride from the organic phase containing most of the dioctyltin and trioctyltin compounds; (3) optionally purifying said aqueous phase comprising monooctyltin trichloride from undesired side products by washing said aqueous phase with an organic solvent; and (4) recovering monooctyltin trichloride from said aqueous phase comprising monooctyltin trichloride.

A method for purifying a tin compound, including: making an inert gas pass through in, or on a surface of, a liquid containing a tin compound represented by a chemical formula RSnX.sub.3, where R represents a hydrocarbon group having 1 to 30 carbon atoms optionally substituted with a halogen atom, and X represents a hydrolysable substituent, to perform stripping, before or after a distillation step of the tin compound.

The purification of monoalkyl tin trialkoxides and monoalkyl tin triamides are described using fractional distillation and/or ultrafiltration. The purified compositions are useful as radiation sensitive patterning compositions or precursors thereof. The fractional distillation process has been found to be effective for the removal of metal impurities down to very low levels. The ultrafiltration processes have been found to be effective at removal of fine particulates. Commercially practical processing techniques are described.

The present disclosure is related to organotin cluster photoresists and stabilization methods, particularly for extreme ultraviolet radiation (EUV) photolithography. The organotin cluster photoresists comprise one or more represented by chemical formulas [RR.sup.1Sn].sub.3E.sub.3, and [RSn].sub.4E.sub.6. The stabilization methods include the application of organic molecules as additives to stabilize organotin cluster photoresists.

Monoorgano tin trialkoxide compounds having chemical formula RSn(OR).sub.3 and containing less than about 5 mol % tin tetraalkoxide are described. R is a linear or branched, unsaturated hydrocarbon group having about 2 to about 4 carbon atoms and each R is independently trimethylsilyl, phenyl, or a linear or branched, optionally fluorinated, alkyl group having about 1 to about 5 carbon atoms. Methods for synthesizing and purifying these compounds are also provided. The monoorgano tin compounds may be used for the formation of high-resolution EUV lithography patterning precursors and are attractive due to their high purity and minimal concentration of diorgano tin impurities.

A synthetic process of producing liquid tin(II) alkoxides for use as either catalysts in the synthesis of lactide or as initiators in the polymerization of cyclic ester monomers to yield biodegradable polyesters is described. The synthetic process employs anhydrous tin(II) chloride dissolved in n-heptane mixed with dry diethylamine. Alcohols, ROH, in which the R groups are n-C.sub.4H.sub.9, n-C.sub.6H.sub.13, and n-C.sub.8H.sub.17 are added to the reaction mixture and stirred for 12 hours. The reaction mixture is then filtered under nitrogen or argon before being evaporated to dryness to yield the three tin(II) alkoxides, namely: tin(II) n-butoxide, tin(II) n-hexoxide, and tin(II) n-octoxide. All three tin(II) alkoxides are viscous, dark yellow liquids which are highly soluble in most common organic solvents. Furthermore, they can all be stored under an inert atmosphere for long periods without any significant change in their reactivity and, therefore, in their effectiveness as catalysts/initiators.

Aspects of the disclosure relate to methods for producing organotin compounds with high purity, which may involve the use of specific additives or reaction conditions. Methods for purifying organotin compounds and suppressing the formation of impurities in organotin compounds are also described.

A pure composition comprises a monoalkyltin trialkoxide compound represented by the chemical formula RSn(OR).sub.3 or a monoalkyl tin triamide compound represented by the chemical formula RSn(NR.sub.2).sub.3 and no more than 4 mole % dialkyltin compounds relative to the total tin amount, where R is a hydrocarbyl group with 1-31 carbon atoms, and wherein R is a hydrocarbyl group with 1-10 carbon atoms. Methods are described for the formation of the pure compositions. A solid composition comprises a monoalkyl triamido tin compound represented by the chemical formula RSn(NRCOR).sub.3, where R is a hydrocarbyl group with 1-31 carbon atoms, and where R and R are independently a hydrocarbyl group with 1-10 10 carbon atoms. The compositions are suitable for the formation of resist compositions suitable for EUV patterning in which the compositions have a high EUV absorption.

A method for producing a tin compound represented by formula (A1) with a purity of 95 mol % or higher, involves a step of distilling the tin compound, in which the number of plates of the distillation is 10 or more, and the reflux ratio is 30 or less.

RSnX.sub.3(A1)

In formula (A1), R is an organic group with 1 to 30 carbon atoms, and may be substituted with halogen, oxygen atoms, or nitrogen atoms. X is selected from OR and NR.sub.2. R is an organic group with 1 to 10 carbon atoms, and part may be substituted with halogen, oxygen atoms, or nitrogen atoms. When there are multiple R groups in the molecule, they may have the same or different structures, and they may be bonded to each other to form a cyclic structure.

Provided is a facile process for preparing certain organotin compounds having alkyl and alkylamino substituents. The process provides organotin precursor compounds, for example tris(dimethylamido)isopropyl tin, in a highly pure form. As such, the products of the process are particularly useful in the deposition of high-purity tin oxide films in, for example, extreme ultraviolet light (EUV) lithography techniques used in microelectronic device manufacturing.