Influence of Tin Impurities on the Generation and Annealing of Thermal Oxygen Donors in Czochralski Silicon at 450°C

Abstract

The beneficial influence of Sn doping of Si materials on the radiation hardness has triggered interest in this material. It is therefore essential to have a good insight in the impact of Sn on the fundamental defect behavior. This report gives a systematic study of the effect of the Sn impurities on the generation and annealing kinetics of oxygen‐containing thermal donors formed during a 450°C anneal step. Special attention is given to the influence of a thermal preheat treatment at 800°C and the important role played by oxygen microfluctuations. The latter act as precursors for the thermal donor formation. The original Kaiser‐Frisch‐Reiss model, developed for explaining the experimental results in Sn‐free Czochralski Si and based on hetero‐ and homogeneous precipitation processes, points to the beneficial role of Sn doping on the thermal donor properties. © 2000 The Electrochemical Society. All rights reserved.