Often used to reduce the RC delay in integrated circuits are dielectric films of porous organosilicates which have a silica like backbone with alkyl or aryl groups (to add hydrophobicity to the materials and create free volume) attached directly to the Si atoms in the network. Si--R bonds rarely survive an exposure to plasmas or chemical treatments commonly used in processing; this is especially the case in materials with an open cell pore structure. When Si--R bonds are broken, the materials lose hydrophobicity, due to formation of hydrophilic silanols and low dielectric constant is compromised. A method by which the hydrophobicity of the materials is recovered using a novel class of silylation agents which may have the general formula (R.sub.2N).sub.XSiR'.sub.Y where X and Y are integers from 1 to 3 and 3 to 1 respectively, and where R and R' are selected from the group of hydrogen, alkyl, aryl, allyl and a vinyl moiety. Mechanical strength of porous organosilicates is also improved as a result of the silylation treatment.