Postnucleation surface transport-kinetical phenomena and morphological instability in film deposition from vapor

The problem of transition of the postnucleation surface profile to continuous growth in the chemical vapor deposition process is considered. The developed numerical model includes a comprehensive set of transport-kinetical phenomena ongoing on the growth interface taking into account the effect of surface self-shadowing from the impinging species feeding the growth. This effect takes place when the characteristic length scale of surface profiles provided by the nucleation stage is lower than the free mean path of the gas species. The effect is shown to be able to destabilize the surface morphology in cases when the surface concentration is held far from the adsorption-desorption equilibrium and the surface profile length provided by the nucleation stage is considerably larger than the surface diffusion length of the growth species. Conditions under which the postnucleation surface smoothing may take place are specified. Experimentally feasible steps for postnucleation surface smoothing are discussed. (C) 2001 American Institute of Physics.