Structure and electronic properties of trivacancy and trivacancy‐oxygen complexes in silicon

Abstract We have recently found that the silicon trivacancy (V₃) is a bistable defect that can occur in fourfold coordinated and (110) planar configurations for both the neutral and singly negative charge states [V. P. Markevich et al., Phys. Rev. B 80, 235207 (2009)]. Acceptor levels of V₃ in both these configurations have been determined. It has also been shown that at T > 200 °C, the interaction of mobile trivacancies with interstitial oxygen atoms results in the formation of V₃O complex with the first and second acceptor levels at E_c −0.46 and −0.34 eV. In the present work we identify donor levels arising from V₃ and V₃O complexes by means of deep level transient spectroscopy (DLTS) and high‐resolution Laplace DLTS on n⁺p silicon structures irradiated with 6 MeV electrons, combined with density functional modeling studies. It is found that both defects possess two donor levels in the (110) planar configurations. First donor levels at E_v +0.19 and +0.235 eV, and the second donor levels at E_v +0.105 and +0.12 eV are found for the V₃ and V₃O complexes, respectively.