SiO2thin films were deposited with atomic layer control using binary reaction sequence chemistry. TheSiO2growth was accomplished by separating the binary reactionSiCl4+2H2O→SiO2+4HClinto two half-reactions. Successive application of the half-reactions in an ABAB&ellip; sequence producedSiO2deposition at temperatures between 600 and 800 K and reactant pressures of 1–10 Torr. TheSiO2growth was monitored using ellipsometry versus substrate temperature and reactant exposure time. The maximumSiO2deposition per AB cycle was 1.1 Å/AB cycle at 600 K. The surface topography measured using atomic force microscopy was extremely flat with a roughness nearly identical to the initial substrate. ©1997 American Institute of Physics.