The binding energy of vacancy clusters generated by high-energy ion implantation and annealing in silicon

We have measured the evolution of the excess vacancy region created by a 2 MeV, 10 sup (16)/cm sup 2 Si implant in the silicon surface layer of silicon-on-insulator substrates. Free vacancy supersaturations were measured with Sb dopant diffusion markers during post-implant annealing at 700degrees, 800degrees, 900C, while vacancy clusters were detected by Au labeling. We demonstrate that a large free vacancy supersaturation exists for short times, during the very early stages of annealing between the surface and the buried oxide (1micron below). Afterwards, the free vacancy concentration returns to equilibrium in the presence of vacancy clusters. These vacancy clusters form a low temperatures and are stable to high temperatures, i.e. they have a low formation energy and high binding energy.