Formation of Cu precipitates by ion implantation and thermal annealing for the growth of oxide nanorods

Cu precipitates were formed on Si(1 0 0) by 200 keV Cu ion implantation and subsequent annealing at 773 K. The shape of the Cu precipitates evolved from a large rectangle to a small elongated pyramid with increasing annealing time, and this shape evolution seemed to result from the epitaxial formation of Cu precipitates. The average density of Cu precipitates monotonously increased and the average diameter of Cu precipitates decreased with increasing annealing time up to 1 h. These indicate that the morphology, size and average density of Cu precipitates can be controlled by varying annealing time, and that Cu ion implantation and subsequent annealing were effective in producing a substrate dispersed with catalytic particles for oxide nanorods growth.