Effect of the amorphous thin layer on the surface growth of amorphous/crystalline binary multilayer films

The effect of the amorphous thin layer on the surface growth of amorphous/crystalline binary multilayer films has been studied by using a continuum model. It is shown that both the surface roughness and the growth exponent of amorphous/crystalline binary multilayer films decrease with increasing thickness ratio between amorphous and crystalline layers. Our simulations have also revealed, in contrast to the monotonous rise in surface roughness observed in single-layer films grown on flat substrates, the surface growth of a multilayer film consists of two processes: interface smoothing and roughening, namely the film roughness decreases during the growth of amorphous thin layers but increases monotonously during the growth of crystalline thin layers. The observed interface smoothing and roughening can be obviously influenced by the change in the thickness ratio between amorphous and crystalline layers. The rise in thickness ratio between amorphous and crystalline layers enhances the interface smoothing effect but lowers the interface roughening effect and consequently shows a marked smoothing effect on the surface roughness.