Investigation of defects in reactive ion-implanted silicon

Abstract

The reactive ion implantation in silicon at different fluence levels varying from 5 × 10 16 to 1 × 10 18 ions cm −2 was carried out at 30 keV to synthesize silicon dioxide (SiO 2), silicon nitride (Si 3N 4) and silicon oxynitride (Si x O y N z ) layers at room temperature. The electron spin resonance (ESR) measurements were performed on these samples to study the defects. The rapid thermal annealing (RTA) behaviour of defects in nitrogen ambient was also studied. The room temperature ESR studies show a defect center related to silicon dangling bonds at g∼2.0040–2.0051. This defect center almost disappears after RTA at 1073 K for 5 min. The spin density is found to depend strongly on the ion-fluence. The low temperature studies indicate the presence of an additional center associated with interface defects at g∼1.999 for low fluence implanted samples. However, this defect center was not observed for samples implanted with high fluence levels (⩾5 × 10 17 ions cm −2).