Passivation of shallow impurities in Si by annealing in H2 at high temperature

Abstract

We have found by infrared absorption that shallow acceptors in Si can be passivated throughout the bulk of a semiconductor sample several mm thick by annealing in H2 at high temperature (≳900 °C) and quenching to room temperature. The total number of shallow centers passivated in such samples is comparable to the number in highly doped surface layers passivated in a hydrogen plasma at lower temperature (typically <400 °C). The importance of bulk passivation techniques is discussed.