Ion beam synthesis of buried SiC layers in silicon: Basic physical processes

For the ion beam synthesis (IBS) of buried stoichiometric epitaxial layers of 3C-SiC in silicon, a complicated structure in the as-implanted state has been identified as a favourable starting structure prior to annealing. It consists of a nearly rectangular depth distribution of equally sized, orien ted 3C-SiC nanocrystals sandwiched between two amorphous zones. The basic p hysical processes leading to such a distribution of amorphous and crystalli ne phases during high-dose, high-temperature carbon implantation into silic on are reviewed in this article. In particular, the precipitation of carbon in a self-organized lattice of amorphous inclusions, the formation of stab le 3C-SiC nuclei via precursors, beam-induced nucleation of SiC in amorphou s Si:C, the different growth of crystalline SiC precipitates in crystalline and amorphous silicon and the ballistic destruction of SiC nanoclusters by the continued bombardment with energetic ions - resulting in a carbon-indu ced amorphization at elevated temperatures - are described. (C) 2001 Elsevi er Science B.V. All rights reserved.