The annealing behavior of the divacancy (${\mathit{V}}_2$) acceptor levels in silicon is investigated with the use of Schottky-barrier structures formed by the deposition of copper on n-type silicon irradiated with 2-MeV electrons. At temperatures below ∼150 °C an anomalously high annealing rate of the ${\mathit{V}}_2$ centers is observed, and we believe that the fast-diffusing interstitial ${\mathrm{Cu}}^{+}$ passivates their electrical activity and forms neutral complexes. In the temperature range 150–200 °C, where the metal-rich silicide η’-${\mathrm{Cu}}_3$Si forms, the concentration of ${\mathit{V}}_2$ remains almost constant, and we find no evidence for the injection of silicon self-interstitials during the formation of η’-${\mathrm{Cu}}_3$Si, in contrast to recent experiments.

• Received 5 February 1991

DOI:https://doi.org/10.1103/PhysRevLett.66.3028