LOCAL ORDERING AND LATERAL GROWTH OF INITIAL THERMAL OXIDE OF SI(001)

The initial stages of the thermal (600 degrees C) oxide growth of Si ( 001) clean surfaces were studied by scanning tunneling microscopy (STM ). Oxide growth starts from both step edges and terraces. At 120L, alm ost the entire surface was covered by oxides. Steps could still be ide ntified, and the apparent roughness had a local minimum at this O-2 ex posure. These results indicate that the first layer is oxidized quite uniformly. Some local orderings of the initial oxides were observed on the terraces, which may enhance the oxide growth in the lateral (para llel to the surface) direction.