The formation of the divacancy-oxygen centre (V2O) in p-type Czochralski-grown silicon was investigated by means of deep-level transient spectroscopy. The donor state (+/0) of V2O was located at ~Ev + 0.23eV (Ev denotes the valence band edge) and emerges during heat treatment above 200C at the expense of the divacancy centre (V2). A concurrent transition takes place between the single-acceptor states of V2 and V2O, as unveiled by the injection of electrons through optical excitation during the trap filling sequence of the deep-level transient spectroscopic measurements. Further, a defect with an energy level at ~Ev + 0.09eV evolved in close correlation with the growth of V2O but at a factor of ~5 to 6 lower in concentration. In the literature, the Ev + 0.09eV level had previously been attributed to a double-donor state of V2O but this assignment could be ruled out by the present data favouring a complex formed between migrating V2 centres and a competing interstitial oxygen trap. In addition, a level at ~Ev + 0.24eV occurred also during the heat treatment above 200C and was tentatively assigned to the trivacancy-oxygen centre (V3O).

Formation of Donor and Acceptor States of the Divacancy-Oxygen Centre in p-Type Cz-Silicon. N.Ganagona, B.Raeissi, L.Vines, E.V.Monakhov, B.G.Svensson: Journal of Physics - Condensed Matter, 2012, 24[43], 435801