Abstract

Thin SiO₂ films were deposited with atomic layer control onto Si(100) and on Al₂O₃ films grown on Si(100) using binary reaction sequence chemistry. The atomic layer controlled growth was accomplished by separating the binary reaction SiCl₄ + 2H₂O --> SiO₂ + 4HCl into two half-reactions: where the asterisks designate the surface species. If each half-reaction is self-limiting and goes to completion, then successive application of the A and B half-reactions in an ABAB… sequence should produce layer-by-layer SiO₂ deposition. The atomic layer controlled growth of the SiO₂ films was achieved at temperatures between 600-800 K and reactant pressures of 1 - 10 Torr. The SiO₂ growth rates were monitored with an in-situ spectroscopic ellipsometer versus deposition temperature and reactant exposure time. The surface topography of the deposited SiO₂ films was measured using atomic force microscopy (AFM). The AFM images revealed that the SiO₂ films were extremely flat with a roughness nearly identical to the initial substrate surfaces.

© 1997 Optical Society of America