Patent ID: 8466229

Claim:
A method of producing a composition for forming a silica-based film, the method comprising: a step of obtaining a solution by dissolving a compound represented by the following general formula (1) in an aprotic solvent: R 1 n SiX 4-n (1) wherein R 1 is an H or F atom, a group containing a B, N, Al, P, Si, Ge, or Ti atom, or an organic group having a carbon number of 1 to 20; X is a hydrolyzable group; and n is an integer of 0 to 2; R 1 being either identical or different when n is 2; X being either identical or different when n is 0 to 2; a step of obtaining a polysiloxane solution by hydrolyzing and condensing the compound after adding an inorganic acid catalyst to the solution; a step of removing a solvent in the polysiloxane solution so that the final composition for forming a silica-based film contains said aprotic solvent in an amount of at least 90% by mass to the total amount of the solvent, and a step of combining an onium salt with the polysiloxane solution after the removing step, wherein the content of the onium salt is 0.001 mass ppm to 0.5 mass % based on the total weight of the composition for forming a silica-based film.