Modeling of the depletion of the amorphous-silicon surface during hemispherical grained silicon formation

A model, based on surface energy minimization under nonequilibrium conditio ns, is presented to describe the evolution of the amorphous silicon (a-Si) topography near the hemispherical grained silicon. The evolution of the dep letion area can be explained by a combination between capture of silicon (S i) atoms at the grain boundary and energy minimization of the surrounding a -Si surface. Grain depletion dependence on annealing time was measured by m eans of transmission electron microscopy. The simulated results agree well with the real observations. This approach is presented as a first step in p hysically based modeling of HSG formation. (C) 2000 American Institute of P hysics. [S0021-8979(00)06323-4].