MOLECULAR-BEAM STUDY ON SCATTERING AND STICKING OF MOLECULAR-OXYGEN AT SI(100)

Molecular beam techniques have been used to probe the dynamics of oxidation of a Si(100) surface as a function of incident energy E(i), incident angle theta-i and surface temperature T(s). The angular distributions of scattered O2 from Si(100) are clearly bimodal exhibiting both trapping desorption and direct inelastic scattering. The initial sticking probability, S(o), is measured with AES as a function of E(i). At E(i) = 0.09 eV, where the trapping-desorption process is dominant, S(o) decreases with T(s). On the other hand, an E(i) = 0.9 eV, S(o) increases with T(s). Since the direct inelastic scattering is dominant at this energy, this fact indicates that sticking of O for high E(i) occurs without physisorption.