Abstract: This invention relates to materials and processes for selective deposition of silica films on non-metallic areas of substrates while avoiding any significant deposition on metallic conductive areas. Silica sealed the surface pores of a porous dielectric by the reaction of an aluminum-containing compound with an alkoxysilanol. Metal layers are protected from this deposition of silica by adsorption of a partially fluorinated alkanethiol. This invention provides processes for producing semi-porous dielectric materials wherein surface porosity is significantly reduced or removed while internal porosity is preserved to maintain a desired low-k value for the overall dielectric material. At the same time, a clean metal surface is produced, so that low electrical resistances of connections between copper layers are maintained. The combination of low-k dielectric constant and low resistance allows construction of microelectronic devices operating at high speeds.