Coating liquid for forming a silica-containing film with a low-dielectric constant

A coating liquid for forming a silica-containing film with a low-dielectric constant, comprising a polymer composition consisting essentially of (i) a polysiloxane and (ii) a readily decomposable resin,

• said polymer composition being contained in an organic solvent in an amount of 5 to 30% by weight based on the total weight of the coating liquid,
• said polysiloxane being a reaction product between fine particles of silica and a hydrolyzate of at least one alkoxysilane represented by the following formula (I):
• XnSi(OR)4−n (I)
• wherein X represents a hydrogen atom, a fluorine atom, an unfluorinated or fluorinated alkyl group of 1 to 8 carbon atoms, an aryl group or a vinyl group;
• R represents a hydrogen atom, an alkyl group of 1 to 8 carbon atoms, an aryl group or a vinyl group;
• and n is an integer of 0 to 3,
• said readily decomposable resin being capable of being decomposed or vaporized by heating at a temperature of not more than 500° C. or by irradiating with ultraviolet radiation, infrared radiation, electron beam, X-ray or oxygen plasma and having a number-average molecular weight of 500 to 50,000 in terms of polystyrene, and
• said polymer composition being an interpenetrated polymer composition in which the polysiloxane and the readily decomposable resin are entangled in each other on the molecular chain level.