Depth Profile Analysis of Metals Gettered by Oxide Precipitates in Silicon Substrates

Abstract

We have experimentally demonstrated the depth profiles of metals gettered by oxide precipitates in silicon wafers with different densities and sizes of oxide precipitates. It has been found that although the total surface area of the oxide precipitates per unit volume is dispersed uniformly through the wafers or slightly increases with increasing depth below the denuded zone (DZ), more metals are gettered at around the depth where the total surface area of the oxide precipitates sharply increases just below the DZ. It is considered that metals diffused in the DZ are gettered by oxide precipitates near the DZ during cooling, while metals diffused in the deeper regions are dispersedly gettered by each oxide precipitate in deeper regions during cooling.