Formation of supersaturated alloys by ion implantation and pulsed-laser annealing

Supersaturated substitutional alloys formed by ion implantation and rapid liquid-phase epitaxial regrowth induced by pulsed-laser annealing have been studied using Rutherford-backscattering and ion-channeling analysis. A series of impurities (As, Sb, Bi, Ga, In, Fe, Zn, Cu) have been implanted into single-crystal (001) orientation silicon at doses ranging from 1 x 1015/cm2 to 1 x 1017/cm2. The samples were subsequently annealed with a Q-switched ruby laser (energy density approx. 1.5 J/cm2, pulse duration 15 x 10-9 sec). Ion-channeling analysis shows that laser annealing incorporates (Ga, In) and (As, Sb, Bi) impurities into substitutional lattice sites at concentrations far in excess of the equilibrium solid solubility. Channeling measurements indicate the silicon crystal is essentially defect free after laser annealing