Correlated annealing and formation of vacancy-hydrogen related complexes in silicon

We report on a deep level transient spectroscopy study of annealing kinetics of a deep, vacancy-hydrogen related level, labeled E5^*, at 0.42 eV below the conduction band in hydrogen-implanted n-type silicon. The E5^* annealing correlates with the formation of another commonly observed vacancy-hydrogen related level, labeled E5, at 0.45 eV below the conduction band. The annealing of E5^* and the formation of E5 exhibit first-order kinetics with an activation energy of 1.61  ±  0.07 eV and a pre-factor of ~10¹³-10¹⁴ s^-1. The pre-factor indicates a dissociation or structural transformation mechanism. The analysis of electron capture cross-sections for E5^* and E5 reveals considerable transition entropies for both states and a temperature dependent capture cross-section for E5^*. Two possible identifications of E5^* and E5 are put forward. Firstly, E5^* can be attributed to V ₂H₂(-/0) or V ₂H₃(-/0), which dissociate with the emission of VH (E5). Secondly, E5^* and E5 can be assigned to two different configurations of V ₃H.