Shape Transition of Nanostructures created on Si(100) surfaces after MeV   Implantation
  We have studied the modification in the Surface morphology of the Si(100) surfaces after 1.5 MeV Sb implantation. Scanning Probe Microscopy has been utilized to investigate the ion implanted surfaces. We observe the formation of nano-sized defect features on the Si surfaces for various fluences. These nanostructures are elliptical in shape and inflate in sizefor higher fluences. Furthermore, these nanostructures undergo a shape transition from an elliptical shape to a circular-like at a high fluence. We will also discuss the modification in surface roughness as a function of Sb fluence. 
S. Dey, D. Paramanik, V. Ganesan, S.Varma