Depth Profile Analysis of Metals Gettered By Bulk Micro-Defects (BMDs) in Silicon Substrates

Abstract

We have experimentally demonstrated the depth profiles of metals gettered by BMDs in silicon wafers with different densities and sizes of BMDs. It has been found that although the total surface area of the BMDs 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 BMDs sharply increases just below the DZ. It is considered that metals diffused in the DZ are gettered by BMDs near the DZ during cooling, while metals diffused in the deeper regions are dispersedly gettered by each BMD in deeper regions during cooling.