Studies of InP nano dots formation after keV Ar+ irradiation

Temporal evolution of nano dots fabricated, in off-normal geometry but in the absence of rotation, on InP(1 1 1) surfaces by 3 keV Ar ion sputtering is reported here. After 10 min of sputtering, self-assembled nano dots with mean diameter of 24 ± 4 nm display square short range weak ordering. Fully developed square celled arrays of dots with mean diameter of 90 ± 26 nm, are seen beyond the non-linear coarsening regime at the critical time of 40 min. Inverse coarsening of dots in conjunction with surface smoothening, never seen in earlier studies of dot evolution, is observed beyond the critical time.