Silsequioxane-titania hybrid polymers
View Patent ↗The invention relates to silsesquioxane-titania hybrid polymers, wherein the titania domain size is less than about five nanometers. Such polymers are useful, for example, to form anti-reflection coatings in the fabrication of microelectronic devices.
1. A method for producing a silsesquioxane-titania hybrid polymer, comprising the steps of: (a) combining an organo-titanate with a silsesquioxane polymer by either (i) adding a solution of an organo-titanate in an aprotic solvent to a solution of a silsesquioxane polymer in an aprotic solvent to form an intermediate, the organo-titanate having the formula (RO) 4 Ti, wherein R is an alkyl, aryl or alkaryl group having from 1-20 carbons and optionally containing one or more heteroatoms, the silsesquioxane polymer having a weight average molecular weight of at least 2500 per mole or (ii) adding a solution of a silsesquioxane polymer in an aprotic solvent to a solution of an organo-titanate in an aprotic solvent to form an intermediate, the organo-titanate having the formula (RO) 4 Ti, wherein R is an alkyl, aryl or alkaryl group having from 1-20 carbons and optionally containing one or more heteroatoms and the silsesquioxane polymer has a weight average molecular weight of at least 2500 grams per mole; and (b) adding water to the intermediate to form the silsesquioxane-titania hybrid polymer having titania domains of less than about 5 nm.
2. The method of claim 1 , wherein the silsesquioxane polymer comprises alkenyl and aryl groups.
3. The method of claim 2 , wherein the alkenyl groups of the silsesquioxane polymer are vinyls.
4. The method of claim 2 , wherein the aryl group of the silsesquioxane polymer is phenyl.
5. The method of claim 1 , wherein R is n-butyl.
6. The method of claim 1 wherein the solution of silsesquioxane polymer is added to the solution of organo-titanate.
7. The method of claim 6 , wherein the silsesquioxane polymer has a weight average molecular weight of less than 30,000 grams per mole.
8. The method of any of claim 6 , wherein the silsesquioxane polymer has a weight average molecular weight in the range of from 2,500 to 12,000 grams per mole.
9. A coating comprising the silsesquioxane-titania hybrid polymer made according to the method of claim 1 .
10. A method for producing a silsesquioxane-titania hybrid polymer, comprising the steps of: mixing an organo-titanate, one or more organo-silanes, water and acid to form the silsesquioxane-titania hybrid polymer, the organo-titanate having the formula (RO) 4 Ti, wherein R is an alkyl, aryl or alkaryl group having from 1-20 carbons and optionally containing one or more heteroatoms, the one or more organo-silanes having the formula XaSiZ4- a wherein a is 1 or 2 or 3, provided in at least some of the organo-silane a is 1; wherein X is an alkyl, alkenyl, aryl or alkaryl group having from 1-20 carbons and optionally containing one or more heteroatoms; and wherein Z is hydroxy or a hydrolyzable group and can be the same or different in each occurrence on the organo-silane compound.
11. The method of claim 10 , wherein the silsesquioxane-titania hybrid polymer comprises alkenyl and aryl groups.
12. The method of claim 11 , wherein the alkenyl groups of the silsesquioxane-titania hybrid polymer are vinyls.
13. The method of claim 11 , wherein the aryl group of the silsesquioxane-titania hybrid polymer is phenyl.