ELECTRICAL AND THERMAL-PROPERTIES OF STRUCTURALLY METASTABLE IRON-BORON PAIRS IN SILICON

Structurally metastable iron-boron pairs in silicon have been detected using dark- or photocapacitance transient techniques combined with mi nority-carrier injection below 200 K. Five levels at E(C)-0.43, 0.46, 0.52, and 0.54 eV and E(V) + 0.53 eV are observed as the metastable de fects after the injection. The creation and annihilation behaviors of these defects by the injection are investigated in detail and discusse d on the basis of the theory of recombination-enhanced defect reaction . The transmutations for respective defects are confirmed by isochrona l anneals and the reaction kinetics are studied by isothermal anneals. These kinetic studies lead to a model for pair configurations respons ible for these defect levels. The configuration-coordinate (CC) descri ption for these metastable pairs is shown to account for all electrica l and thermal properties. The CC model shows us why the metastability for the iron-boron pair cannot be observed in thermal equilibrium.