A new approach to detect small-sized oxygen precipitates in Si wafers using reactive ion etching

A new technique to detect oxygen precipitates in Si wafers using highly selective reactive ion etching is presented. In this technique, oxygen precipitates in Si wafers are detected as Si cones which have an oxygen precipitate at the tip of each cone. It was demonstrated that this technique was capable of detecting nanometer-sized oxygen precipitates and estimating their size and morphology. In addition, the technique was found to evaluate the depth distribution of the precipitates with an accuracy of 0.3 μm. The detectable size limit and depth resolution was found to be about ten times higher than those of LST. Moreover, relationships of the size or density of oxygen precipitates to OSF formation and GOI characteristics were demonstrated using this technique.