Thermal donor formation in CZ-silicon with reference to dimers, trimers and V–O interaction

Silicon wafers with different initial oxygen and carbon concentrations annealed in air ambient at 650 °C revealed that the new donor concentration is more for the sample with high carbon content at same values of oxygen reduction. Vacancy–oxygen interaction plays an important role resulting in the interaction of dimers and trimers with the vacancies consequently forming Vm–On defects. These defects get trapped at silicon interstitial releasing a dimer and trimer. Dimers also interact with other defects such as CsO defects in CZ-Silicon. Thermal donors (TDs) are formed through the aggregation of rapidly diffusing dimers. Dimers also encounter with third Oi atom and form trimers. They may encounter with next Oi and 4Oi atoms experience sufficient lattice strain to switch them into di-y-lid structure. A new model based on trimers is proposed to account for the formation of thermal donors. This article aims at minimizing the uncertainty providing amicable explanation to the proposed structural model.