A Method for Detecting Oxygen Precipitates in Silicon Crystals Using Highly Selective Anisotropic Reactive Ion Etching

Abstract

This work presents a new method for detecting oxygen precipitates in Si wafers. The method utilizes a reactive ion etching (RIE) process. Oxygen precipitates are detected as needle-shaped silicon cones, which are formed under the precipitates by etching under a condition that the etching ratio of Si is much greater than that of SiO2. It was demonstrated that this method was capable of detecting nanometer-sized oxygen precipitates and estimating their size and morphology.