Surface roughening and radial separation distribution studies on InP(1Â 1Â 1) surfaces after MeV Sb Implantation

We have investigated the topography and the radial separation distribution of the InP(1 1 1) surfaces after 1.5 MeV Sb2+ implantation. Power spectral density has been evaluated by utilizing the scanning probe microscopy (SPM) images of the MeV implanted InP(1 1 1) surfaces. We find that the exponent, n, increases up to the fluence of 1 × 1014 ions/cm2 and is found to be n = 4.36 at this fluence suggesting that the diffusion processes are crucially determining the evolution of InP surface. For higher fluences a slight decrease in n is seen. We have also studied the radial separation distribution of the nanostructures that form on the InP(1 1 1) surfaces after MeV Sb implantation. The radial separation distributions, for all the fluences, collapse on a curve. Moreover, although for Sb fluence of 1 × 1011 ions/cm2 the nanostructures are randomly distributed on the InP surface, for higher fluences a clustering of nanostructures at r ≈ 〈R〉, suggesting a non-uniform distribution of nanostructures is observed. The clustering may be a result of surface diffusion or strain.