Dry and wet etching properties of thermally grown silicon dioxide layer after N + ion implantation and annealing

Abstract

We have investigated thermal oxidation of silicon, and dry and wet etching characteristics of the oxide layer after N + (Ar −) ion implantation and subsequent annealing. An oxidation resistance is observed in the N + implanted silicon with doses more than 1 × 10 15 N + /cm 2. The etch rate of the oxide layer in a diluted HF solution is enhanced with a dose of 1 × 10 15 N + / cm 2, whereas an etching resistance is observed for the samples with doses more than 2 × 10 15 N + /cm 2. However, only the etching resistance appears in the dry etching. These resistances are also observed by argon implantation and easily removed by subsequent annealing. These results indicate that the oxidation and etching resistances are related to a thin oxynitride formation and the surface modification by ion implantation.