Self-assembly of faceted Ni nanodots on Si(111)

We report the formation of Ni nanodots on Si(111). Island density is varied by annealing temperature and time and is studied using atomic force microscopy (AFM) and magnetic force microscopy. Activation energies of 0.09 +/- 0.02 and 0.31 +/- 0.05 eV are observed for the formation of these islands. These are associated with Ni surface self-diffusion across the (111) and (110) Ni facets, respectively. For brief 500 degrees C anneals, regular nanodots are observed with self-limiting sizes of height similar to 16 nm and area 180 nm X 260 nm, while density exhibits a power-law time dependence with exponent 1.13 +/- 0.12. AFM analysis reveals a "truncated hut" shape consistent with (110) top and (111) sidewall surfaces. (c) 2005 American Institute of Physics.