Ion-beam mixing in crystalline and amorphous Si und Ge

Molecular dynamics simulations using Stillinger-Weber-type interatomic potentials were performed in order to investigate ion-beam mixing by 400 eV self-ion implantation at different fluences and temperatures. In general the magnitude of mixing in an amorphous structure was found to be higher than in its crystalline counterpart. This supports the results of earlier calculations (K. Nordlund et al., J. Appl. Phys. 83 (1998) 1238). The trends observed in our simulations are compared to our experimental results on ion beam mixing in crystalline and amorphous isotopically modulated Si and Ge multilayer structures.