Proximity gettering of iron in separation-by-implanted-oxygen wafers

High energy ion implantation of either C or He followed by annealing (proximity gettering) have been used to form gettering layers in separation-by-implanted-oxygen (SIMOX) structures intentionally contaminated with Fe. Analyses by secondary-ion-mass spectroscopy (SIMS) have been carried out to study the redistribution of Fe and to assess the gettering efficiency of these layers. The results obtained have shown that He implants provide no gettering of Fe. Marked depletion of Fe has only been achieved near the C-rich gettering layers.