Microscopic analysis of current-induced domain conversion phenomena on Si(001) vicinal surface

The microscopic mechanism of the current-induced domain conversion phenomena on the Si(001) vicinal surface is studied by taking account of the stability of two types of steps. In the migration process of atoms our model takes four effects into account: the anisotropic migration of the Si(001) reconstructed surface, the anisotropy of the lateral bond between atoms, the electromigration effect and the Schwoebel effect. The kinetic equations for the time evolution of the Si(001) vicinal surface are derived using the pair approximation of the path probability method (PPM), a non-equilibrium statistical method. Our model explains not only the domain conversion phenomena but also the difference in the step structures observed in some experiments. Based on the microscopic kinetics of atoms, the mechanism of the domain conversion is discussed. The results of the PPM calculation are in quantitatively good agreement with those of the Monte Carlo simulation carried out simultaneously by us.