A composition for film formation capable of forming a silica-based coating
film having low water absorption and dielectric constant of 2.1 or lower
and useful as an interlayer insulating film material in semiconductor
devices, etc. The composition contains: (A) a product of hydrolysis and
condensation obtained by hydrolyzing and condensing at least one silane
compound selected from the group consisting of compounds represented by
formula (1), compounds represented by formula (2), and compounds
represented by formula (3) in the presence of a basic catalyst and water,
R.sub.a Si(OR.sup.1).sub.4-a (1)
wherein R represents a hydrogen atom, a fluorine atom, or a monovalent
organic group, R.sup.1 represents a monovalent organic group, and a is an
integer of 1 or 2,
Si(OR.sup.2).sub.4 (2)
wherein R.sup.2 represents a monovalent organic group,
R.sup.3.sub.b (R.sup.4 O).sub.3-b Si--(R.sup.7).sub.d
--Si(OR.sup.5).sub.3-c R.sup.6.sub.c (3)
wherein R.sup.3 to R.sup.6 may be the same or different and each represents
a monovalent organic group, b and c may be the same or different and each
is a number of 0 to 2, R.sup.7 represents an oxygen atom, a phenylene
group, or a group represented by --(CH.sub.2).sub.n --, wherein n is an
integer of 1 to 6, and d is 0 or 1; (B) a compound compatible with or
dispersible in ingredient (A) and having a boiling point or decomposition
temperature of from 250 to 450.degree. C.; and (C) an organic solvent.
