Stable solutions of monoalkyl tin alkoxides and their hydrolysis and condensation products
Precursor solutions for radiation patternable coatings are formed with an organic solvent and monoalkyl tin trialkoxides in which the water content of the solvent is adjusted to be within 10 percent of a selected value. Generally, the water content of the solvent is adjusted through water addition, although water removal can also be used. In some embodiments, the adjusted water content of the solvent can be from about 250 ppm by weight to about 10,000 ppm by weight. With the appropriate selection of ligands, the adjusted precursor solutions can be stable for at least about 42 days, and in some cases at least 8 months.
1. A method for preparing an adjusted precursor solution for a radiation patternable coating comprising a mixture of an organic solvent and a first monoalkyl tin trialkoxide (RSn(OR′) 3 ) having a tin concentration that is from about 0.004 M to about 1.0 M, the method comprising:
mixing the organic solvent and the first monoalkyl tin trialkoxide to form the adjusted precursor solution, wherein the solvent has been adjusted to have a water content to within ±15 percent of a selected water content and wherein the selected water content is greater than zero and no more than 10,000 ppm by weight,
wherein R and R′ are independently a hydrocarbyl ligand with one or more carbon atoms optionally substituted with one of more heteroatom functional groups, wherein the hydrocarbyl ligand comprises an alkyl, an aryl, an alkenyl, or a cycloalkyl group with 1-31 carbon atoms.
2. The method of claim 1 wherein the solvent with the adjusted water content is formed by a process that comprises the addition of water to a stock solvent prior to forming the mixture with the first monoalkyl tin trialkoxide.
3. The method of claim 1 wherein the organic solvent is an alcohol with a melting point of no more than about 10° C. and wherein the adjusted precursor solution is stable for at least 42 days.
4. The method of claim 1 wherein the organic solvent is 4-methyl-2-pentanol.
5. The method of claim 1 wherein the precursor solution has a tin concentration from about 0.01M to about 0.25M.
6. The method of claim 1 wherein the water content of the solvent is adjusted to a value from about 250 ppm to about 10,000 ppm by weight and wherein the adjusted precursor solution is stable for at least 42 days.
7. The method of claim 1 wherein the water content of the solvent is adjusted to a value from about 300 ppm to about 5,000 ppm by weight and wherein the adjusted precursor solution is stable for at least 148 days.
8. The method of claim 1 wherein the first monoalkyl tin trialkoxide comprises monoalkyl tin (Ot-amyl) 3 .
9. The method of claim 1 wherein the first monoalkyl tin trialkoxide comprises t-butyl tin trialkoxide.
10. The method of claim 1 wherein the mixture further comprises as an ingredient a second monoalkyl tin trialkoxide distinct from the first monoalkyl tin trialkoxide.
11. The method of claim 10 wherein the first monoalkyl tin trialkoxide comprises a first monoalkyl tin (Ot-amyl) 3 and the second monoalkyl tin trialkoxide comprises a second monoalkyl tin (Ot-amyl) 3 , wherein the first monoalkyl ligand is distinct form the second monoalkyl ligand.
12. The method of claim 1 wherein the adjusted precursor solution is stable for at least 6 months.
13. A method for forming a radiation patternable coating on a substrate, the method comprising forming a coating of the adjusted precursor solution formed by the method of claim 1 , wherein the coating has an average thickness of no more than about 45 nm and the 3 sigma thickness variation is no more than about 1.15 nm.
14. A solution comprising a mixture of alcohol with a selected water content and a first monoalkyl tin trialkoxide (RSn(OR′) 3 ), wherein the solution has a tin concentration from about 0.004M to about 1.0 M and wherein the selected water content is at least about 250 ppm by weight and wherein the solution is stable for at least 42 days, wherein R and R′ are independently a hydrocarbyl ligand with one or more carbon atoms optionally substituted with one of more heteroatom functional groups, wherein the hydrocarbyl ligand comprises an alkyl, an aryl, an alkenyl, or a cycloalkyl group with 1-31 carbon atoms.
15. The solution of claim 14 wherein the organic solvent is an alcohol with a melting point of no more than about 10° C.
16. The solution of claim 14 wherein the selected water content is adjusted to a value from about 300 ppm to about 10,000 ppm by weight.
17. The solution of claim 14 wherein the first monoalkyl tin trialkoxide comprises monoalkyl tin (Ot-amyl) 3 .
18. The solution of claim 14 wherein the first monoalkyl tin trialkoxide comprises t-butyl tin trialkoxide.
19. The solution of claim 14 wherein the mixture further comprises as an ingredient a second monoalkyl tin trialkoxide distinct from the first monoalkyl tin trialkoxide.
20. The solution of claim 19 wherein the first monoalkyl tin trialkoxide comprises monoalkyl tin (Ot-amyl) 3 and the second monoalkyl tin (Ot-amyl) 3 , wherein the first monoalkyl ligand is distinct form the second monoalkyl ligand.
21. The solution of claim 14 wherein the solution is stable for at least 6 months.
22. A method for patterning a radiation sensitive coating, the method comprising:
forming a coating on a substrate surface with an organometallic precursor solution wherein the organometallic precursor solution has a uniform composition resulting from adjusting the water content of the solvent used to form the adjusted organometallic precursor solution within about ±15% of a selected water content, wherein the selected water content is from about 300 ppm by weight to about 10,000 ppm by weight;
drying the coating; and
irradiating the dried coating to form a latent image.
23. The method of claim 22 wherein the organometallic precursor solution comprises tin.