Effect of an augmented oxygen implant on electron trapping in buried oxides

Abstract

Standard silicon on insulator wafers were prepared by separation by implantation of oxygen. The standard implant of 1.8×1018 O+ cm−2 was augmented by an additional implant of 1017 O+ cm−2. The effect of this augmented implantation of oxygen on electron trap density and cross section was investigated using avalanche injection of electrons into the buried oxide. The shift in the high-frequency capacitance-voltage curve was monitored as a function of injected charge. Analysis of the mid-gap voltage shift versus charge shows no change in the effective density of electron traps. There is a factor of 6.8 decrease in the capture cross section for samples that received the supplemental oxygen implantation.