Point defect injection during nitrous oxidation of silicon at low temperatures

Abstract

In this work we use dislocation loops and boron-doped δ layers to monitor the interstitial injection during nitrous oxidation of silicon at low temperatures (850–950 °C). The interstitials captured by the loops are measured using transmission electron microscopy. The number of Si atoms released after oxynitridation was calculated from the difference between the total number of atoms stored in the loops for oxidizing and inert ambient. We found that this number is larger compared with the same dry oxygen oxidation conditions, although the oxidation rate is lower during oxynitridation in comparison to dry oxidation. Analysis of the earlier data leads to higher supersaturation ratio of interstitials in the former case. This result is also confirmed by measuring the diffusivity enhancement of boron δ layers during oxidation under both ambients.