Simulation of a lattice model for the evolution of Si(001) surfaces exposed to oxygen at elevated temperatures

A lattice model for the evolution of silicon (001) surfaces reacting with an oxygen atmosphere is presented along with results from simulations of the model. Numerous features of experiments are reproduced such as the simultaneous production of pinning centers and of Si etching, leading to long fingers on terraces terminated by oxide islands. Particular study is made of the rate of oxide-island production as a function of oxygen dose, temperature, and the rate of oxygen deposition. The results show the same general trends as scanning tunneling microscopy experiments and simple rate equations in the initial stages of the process but differ significantly in the later stages where the experiments show saturation of the island density while the model does not. From comparison of the simulations and experiments, inferences are drawn concerning the mechanisms which control the nucleation of stable oxide islands.