Surface dopant concentration monitoring using noncontact surface charge profiling

Abstract

This study is concerned with variations of the concentration of active boron dopant in the near surface region of silicon wafers. Boron can be deactivated by pairing with hydrogen or metals, particularly Cu and Fe, all of which may originate from the surface polishing process. The temperature dependence of boron activation is studied using the surface charge profiling method. Based on the determined activation energy of 1.28 eV it was concluded that in the p-type wafers used in this study initially observed boron deactivation was dominated by its interaction with hydrogen introduced during wafer polishing.