Silicide formation and the generation of point defects in silicon.

Abstract

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 \ensuremath{\sim}150 \ifmmode^\circ\else\textdegree\fi{}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 \ifmmode^\circ\else\textdegree\fi{}C, where the metal-rich silicide \ensuremath{\eta}'-${\mathrm{Cu}}_{3}$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 \ensuremath{\eta}'-${\mathrm{Cu}}_{3}$Si, in contrast to recent experiments.