Study of silicon-oxygen interaction with the statical method of secondary ion mass spectroscopy (SIMS)

The interaction of O2 with atomically clean Si surfaces has been studied by UHV secondary ion mass spectroscopy (SIMS). Thermally cleaned and annealed Si (111) surfaces, as well as ion-bombarded Si (111) surfaces, have been investigated. The silicon-oxygen interaction was found to take place in two steps. In step (i) a monoatomical oxide layer on the surface is formed with an initial sticking coefficient for O2 of about 1 and 0.05 for Si (111) and ion-bombarded Si (111), respectively. In step (ii) this monoatomical layer grows very slowly into greater depth.