Patent ID: 7405459

Claim:
A semiconductor device containing a porous film inside, wherein the porous film is formed on a substrate from a composition comprising a zeolite sol having an average particle diameter of 3 to 15 nm, and wherein the zeolite sol is prepared by a method comprising the steps of: a) hydrolyzing and condensing a tetraalkoxylsilane compound expressed by formula (1): Si(OR 1 ) 4 (1) in the presence of a structure-directing agent and a basic catalyst, wherein R 1 represents a straight-chain or branched alkyl group having 1 to 4 carbons, and when there is more than one R 1 , the R 1 s can be independent and the same as or different from each other, and b) heating the tetraalkoxylsilane compound at a temperature of 75° C. or lower.