Chemical, dielectric, thermal, and optical properties of glass films synthesized by chemical vapor reactions from the hydrides are discussed. The binary borosilicate glasses deposited at low temperature from silane, diborane, and oxygen require a thermal densification to approach bulk glass properties. The rate of densification in the temperature range of 770°–800°C is very rapid but water vapor has an accelerating influence, allowing densification at reasonable rates at temperatures as low as 450°C. The thermal expansion match with silicon was sufficiently close to allow the crack‐free coating of wafers with 12µ of glass. Borosilicate films of 5µ thickness on silicon withstood severe thermal shock, temperature cycling, moisture penetration, and corrosion resistance tests. Densified borosilicate of typical compositions had a dielectric constant of 3.8–4.1 and a dissipation factor at 103 Hz of 0.10–0.15. The d‐c dielectric field strength sustained by MIS capacitors made from 1µ thick densified films measured before and after a 1‐yr exposure to room air, was . The properties of vapor‐deposited phosphosilicate glasses and of glasses containing the oxides of aluminum and zinc are briefly described.