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

J Phys Condens Matter. 2019 Jun 12;31(23):235703. doi: 10.1088/1361-648X/ab0bf2. Epub 2019 Mar 1.

Abstract

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.