Stabilizers to inhibit the polymerization of substituted cyclotetrasiloxane
View Patent ↗The present invention is; (a) a process for stabilizing a cyclotetrasiloxane, such as 1,3,5,7-tetramethylcyclotetrasiloxane, against polymerization used in a chemical vapor deposition process for silicon oxides in electronic material fabrication comprising providing an effective amount of a free radical scavenger polymerization inhibitor to such cyclotetrasiloxane; and (b) a composition of a cyclotetrasiloxane, such as 1,3,5,7-tetramethylcyclotetrasiloxane, stabilized against polymerization used in a chemical vapor deposition process as a precursor for silicon oxides in electronic material fabrication, comprising; such cyclotetrasiloxane and a free radical scavenger polymerization inhibitor.
1. A process for stabilizing a cyclotetrasiloxane against polymerization used in a chemical vapor deposition process for silicon oxides in electronic material fabrication and stabilized for extended periods of heating, comprising; providing an effective amount of a free radical polymerization inhibitor to said cyclotetrasiloxane having the following formula:
where R 1-7 are individually selected from the group consisting of hydrogen, a normal, branched or cyclic C 1-10 alkyl group, and a C 1-4 alkoxy group, wherein said free radical scavenger is selected from the group consisting of: 2,6-ditert-butyl-4-methyl phenol, 2,2,6,6-tetramethyl-1-piperidinyloxy, 2,6-dimethylphenol, 2-tert-butyl-4-hydroxyanisole, 3-tert-butyl-4-hydroxyanisole, propyl ester 3,4,5-trihydroxy-benzoic acid, 2-(1,1-dimethylethyl)-1,4 benzenediol, diphenylpicrylhydrazyl, 4-tert-butylcatechol, N-methylaniline, 2,6-dimethylaniline, p-methoxydiphenylamine, diphenylamine, N,N′-diphenyl-p-phenylenediamine, p-hydroxydiphenylamine, phenol, octadecyl-3-(3,5-di-tert-butyl-4 -hydroxyphenyl) propionate, tetrakis (methylene (3,5-di-tert-butyl-4-hydroxy-hydrocinnamate) methane, phenothiazines, alkylamidonoisoureas, thiodiethylene bis (3,5,-di-tert-butyl-4-hydroxy-hydrocinnamate, 1,2,-bis (3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl) hydrazine, tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, cyclic neopentanetetrayl bis (octadecyl phosphite), 4,4′-thiobis (6-tert-butyl-m-cresol, 2,2′-methylenebis (6-tert-butyl-p-cresol), oxalyl bis (benzylidenehydrazide) and mixtures thereof.
2. The process of claim 1 wherein said free radical scavenger is 2,6-di-tert-butyl-4-methyl phenol.
3. A process for stabilizing a cyclotetrasiloxane against polymerization used in a chemical vapor deposition process for silicon oxides in electronic material fabrication, comprising; providing an effective amount of a free radical polymerization inhibitor to said cyclotetrasiloxane having the following formula:
where R 1-7 are individually selected from the group consisting of hydrogen, a normal, branched or cyclic C 1-10 alkyl group, and a C 1-4 alkoxy groups wherein said free radical scavenger is provided in an amount of 10–1000 ppm (wt.).
4. The process of claim 3 wherein said free radical scavenger is provided in an amount of 50–500 ppm (wt.).
5. The process of claim 3 wherein said free radical scavenger is provided in an amount of 50–250 ppm (wt.).
6. The process of claim 3 wherein said free radical scavenger is provided in an amount of 100–200 ppm (wt.).
7. A process for stabilizing 1,3,5,7-tetramethylcyclotetrasiloxane against polymerization for extended periods of heating and caused by oxygen, carbon dioxide and/or nitrogen trifluoride used in a chemical vapor deposition process for silicon oxides in electronic material fabrication comprising providing a free radical scavenger to said 1,3,5,7-tetramethylcyclotetrasiloxane.
8. The process of claim 7 wherein said free radical scavenger is selected from the group consisting of 2,6-di-tert-butyl-4-methyl phenol, 2,2,6,6-tetramethyl-1-piperidinyloxy and mixtures thereof.
9. A composition of 1,3,5,7-tetramethylcyclotetrasiloxane stabilized against polymerization for extended periods of heating and used in a chemical vapor deposition process as a precursor for silicon oxides in electronic material fabrication comprising 1,3,5,7-tetramethylcyclotetrasiloxane and a free radical scavenger polymerization inhibitor.
10. A composition of 1,3,5,7-tetramethylcyclotetrasiloxane, used in a chemical vapor deposition process as a precursor for silicon oxides in electronic material fabrication, and stabilized against polymerization for extended periods of heating, comprising (a) 1,3,5,7-tetramethylcyclotetrasiloxane, (b) a free radical scavenger selected from the group consisting of 2,6-di-tert-butyl-4-methyl phenol, 2,2,6,6-tetramethyl -1-piperidinyloxy, 2-tert-butyl-4-hydroxyanisole, 3-tert-butyl-4-hydroxyanisole, propyl ester 3,4,5-trihydroxy-benzoic acid, 2-(1 ,1-dimethylethyl)-1,4-benzenediol, diphenylpicrylhydrazyl, 4-tert -butylcatechol, N-methylaniline, p-methoxydiphenylamine, diphenylamine, N,N′-diphenyl -p-phenylenediamine, p-hydroxydiphenylamine, phenol, octadecyl-3-(3,5-di-tert-butyl -4-hydroxyphenyl) propionate, tetrakis (methylene (3,5-di-tert-butyl)-4-hydroxy-hydrocinnamate) methane, phenothiazines, alkylamidonoisoureas, thiodiethylene bis (3,5,-di-tert-butyl -4-hydroxy-hydrocinnamate, 1,2,-bis (3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl) hydrazine, tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, cyclic neopentanetetrayl bis (octadecyl phosphite), 4,4′-thiobis (6-tert-butyl-m-cresol), 2,2′-methylenebis (6-tert-butyl-p-cresol), oxalyl bis (benzylidenehydrazide) and mixtures thereof.