Abstract
The reactions of with the clean Si(111) and (100) surfaces have been studied at high temperatures (890°–1350°C) for pressures between . The critical conditions involving pressure and substrate temperature which are necessary for the growth of have been determined, and are consistent with a thermodynamic model modified to include effects due to dissociation and desorption. In addition to clean (active) and (passive) surface regions, an intermediate region is observed and is proposed to be related to a thin, nonpassivating film on the Si surface.