Formation kinetics of trivacancy-oxygen pairs in silicon

Abstract

The formation of donor and acceptor states of the trivacancy-oxygen (V3O) complex in p- and n-type silicon, respectively, has been studied in detail by means of deep level transient spectroscopy. The samples were irradiated with 1.8 MeV protons, and it was found that acceptor and donor states of V3 disappear at annealing temperatures below 200 °C, with a transition from the metastable (110) planar configuration to the stable fourfold coordinated configuration. Annealing above 200 °C unveils the formation of two levels with energy positions at Ec − 0.34 eV and Ec − 0.46 eV in n-type samples and two levels at Ev + 0.24 eV and Ev + 0.11 eV in p-type samples. (Ec and Ev denote the conduction and valence band edge, respectively.) The amplitudes of these levels show an almost one-to-one correlation with those of the V3-related levels occurring after irradiation. In accordance with recent reports in the literature, the emerging levels are ascribed to the V3O complex; single and double negative charge states in n-type samples and single and double positive charge states in p-type samples. By undertaking isothermal formation of the V3O complex in p-type samples which exhibits first-order kinetics, the diffusivity of V3 in the neutral charge state is determined to be (8.5 ± 3.5) × 10−2 exp [−(1.50 ± 0.04) eV/kT] cm2/s.