Silsesquioxane resins and method of using them to form an antireflective coating

1. A method of forming an antireflective coating on an electronic device comprising

(A) applying to an electronic device an antireflective coating composition comprising

(i) silsesquioxane resin having the formula

(PhSiO (3-x)/2 (OR′) x ) m (HSiO (3-x)/2 (OR′) x ) n (MeSiO (3-x)/2 (OR′) x ) o (RSiO (3-x)/2 (OR′) x ) p

where Ph is a phenyl group Me is a methyl group, R is selected from a reactive organic functional group or curable group selected from an acrylate group, an alkenyl group, an epoxy group, and combinations thereof, R′ is hydrogen or a hydrocarbon group, x has a value of 0, 1 or 2; m has a value of 0.01 to 0.97, n has a value of 0.01 to 0.97, o has a value of 0.01 to 0.97, p has a value of 0.05 to 0.95, and m+n+o+p≈1; and

(ii) a solvent, and

(B) removing the solvent and curing the silsesquioxane resin to form an antireflective coating on the electronic device.

2. The method as claimed in claim 1 wherein the antireflective coating composition additionally contains a free radical initiator.

3. The method as claimed in claim 2 wherein the antireflective coating composition additionally contains an additive selected from photo-acid generators, thermal-acid generators, photo-base or thermal-base generators.

4. The method as claimed in claim 2 wherein the antireflective coating composition is applied by spin coating.

5. The method as claimed in claim 2 wherein the silsesquioxane resin is cured by heating.

6. The method as claimed in claim 5 wherein the silsesquioxane resin is cured by heating at 80° C. to 450° C. for 0.1 to 60 minutes.

7. The method as claimed in claim 1 wherein the silsesquioxane resin is cured by ultraviolet light.