SURFACE MODIFICATIONS IN SILICON (100) DUE TO ANTIMONY IMPLANTATION

摘要

The modifications in surface roughness after 1.5 MeV Sb ion implantation have been investigated by the Atomic Force Microscopy. The surface roughness demonstrates three varied behaviours as a function of fluence. An initial low roughness and slow roughening regime gives way to a higher and faster increase in roughness beyond a critical fluence. Finally, a saturation of surface roughness is observed. Surface roughening, thus unexpectedly occurs in 3 stages, governed by the fluence, and increases in a non-monotonous fashion. We have further investigated the lattice disorder, created after ion implantation, by utilizing the technique of Rutherford Back Scattering/Channeling. A Multiple Scattering Formalism has been applied to extract the disorder density from the Rutherford Back Scattering/Channeling data. The disorder density also shows three trends as a function of fluence. Surprisingly, we observe a simple linear relationship between the lattice disorder and the surface roughness up to the fluence of 1 x 10~(14) ions /cm~2. Results demonstrate that though the surface is primarily determined by surface effects, lattice damage may also play a significant role in surface roughness.