Monoalkyl tin compounds with low polyalkyl contamination, their compositions and methods
A pure composition comprises a monoalkyltin trialkoxide compound represented by the chemical formula RSn(OR′) 3 or a monoalkyl tin triamide compound represented by the chemical formula RSn(NR′ 2 ) 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—(NR′COR″) 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 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.
1. A method for forming monoalkyl triamido tin, the method comprising,
reacting a monoalkyltin triamide compound represented by the chemical formula RSn(NR′ 2 ) 3 with an amide (R″CONHR″′) in an organic solvent, wherein R is a hydrocarbyl group with 1-31 carbon atoms, and wherein R′, R″ and R″′ are independently a hydrocarbyl with 1-8 carbon atoms; and
collecting a solid product represented by the formula RSn(NR″′COR″) 3 .
2. The method of claim 1 wherein the monoalkyl tin triamide is at an initial concentration from about 0.1M to about 8M and wherein the solvent is an alkane, an aromatic hydrocarbon, or an ether.
3. The method of claim 1 wherein the amide is added gradually over a period of at least about 2 minutes.
4. The method of claim 1 wherein the solid product is crystalline and has no more than about 1 mole percent relative to tin of contaminants of dialkyltin compounds.
5. The method of claim 1 wherein the monoalkyl triamido tin compound is selectively formed with no more than 1 mole percent polyalkyl tin contamination.
6. The method of claim 1 wherein the monoalkyltin triamide compound has a dialkyl tin contamination that is no more than about 4 mole percent.
7. The method of claim 1 wherein the monoalkyltin triamide compound has a polyalkyl tin contamination that is no more than 1 mole percent.
8. The method of claim 1 wherein R is a t-butyl group or a cyclohexyl group or a cycloheptyl group and R′ is a methyl group.
9. The method of claim 1 wherein R is a t-amyl group or an iso-propyl group.
10. The method of claim 8 wherein R″ and R″′ are methyl groups.
11. A method for forming a monoalkyl tin trialkoxide compound, the method comprising,
reacting a monoalkyl triamido tin compound (RSn(NR″′COR″) 3 ) with an alkali alkoxide compound (QOR′, where Q is an alkali metal atom) in an organic solvent to form a product compound represented by the chemical formula RSn(OR′) 3 , wherein R is a hydrocarbyl group with 1-31 carbon atoms and wherein R′, R″ and R″′ are independently a hydrocarbyl group with 1-10 carbons.
12. The method of claim 11 wherein the alkali alkoxide compound is provided in at least a stoichiometric amount.
13. The method of claim 11 wherein the solvent is an alkane, an aromatic hydrocarbon, or an ether.
14. The method of claim 11 wherein the monoalkyl tin trialkoxide compound is selectively formed with no more than 1 mole percent polyalkyl tin contamination.
15. The method of claim 11 wherein the monoalkyl triamido tin compound has a no more than 1 mole percent polyalkyl tin contamination.
16. The method of claim 11 wherein R is a t-butyl group or a cyclohexyl group or a cycloheptyl group.
17. The method of claim 11 wherein R is a t-amyl group or an iso-propyl group.
18. The method of claim 11 wherein R′ is a tert-amyl group.
19. The method of claim 11 wherein R″ and R″′ are methyl groups.
20. The method of claim 11 wherein Q comprises K, Na, Li, or combinations thereof.