Island formation on a sawtooth patterned substrate

The effect of misfit stress on the formation of a periodic distribution of faceted islands on the free surface of a sawtooth patterned substrate has been theoretically investigated from an energy variation calculation, when the slopes of the film free surface and film-substrate interface are different. It is found that depending on the slope angles and misfit strain, the preferential sites of island formation can be either the peaks or the valleys of the free-surface profile. An energetic phase diagram is provided where the most favorable sites for island nucleation are determined as a function of the different slope angles