A process for forming low dielectric constant dielectric films for the production of microelectronic devices. A dielectric layer is formed on a substrate by chemical vapor depositing a monomeric or oligomeric dielectric precursor in a chemical vapor deposit apparatus, or a reaction product formed from the precursor in the apparatus, onto a substrate, to form a layer on a surface of a substrate. After optionally heating the layer at a sufficient time and temperature to dry the layer, the layer is then exposed to electron beam radiation, for a sufficient time, temperature, electron beam energy and electron beam dose to modify the layer. The electron beam exposing step is conducted by overall exposing the dielectric layer with a wide, large beam of electron beam radiation from a large-area electron beam source.