Rutherford backscattering studies of surface density reduction in ion-implanted and excimer-laser-annealed Ge

Rutherford backscattering (RBS) with 17 MeV 19F is used to obtain depth profiles of ion-implanted Ge both before and after pulsed excimer (XeCl) laser annealing. The as-implanted Ge samples show a reduction of at least a factor of two in the Ge density to a depth of approx. >0.3 μm, and dopant profiles of similar width following room-temperature implantations of In, Sb and Bi at 350 keV. The heavy ion projectile provides distinct kinematic advantages in the present work with a high mass substrate and deep dopant distributions. Annealing with several approx.15 nsec laser pulses (lambda = 308 nm) restores the surface Ge density and produces epitaxial regrowth. For Sb implants the dopant incorporation exceeds the equilibrium solubility limit by a factor of 50. (author)