Electrical properties of buried oxide–silicon interface

A systematic approach of the origin of the generation-recombination mechanism (GR) at the back interface of buried oxide in separation by implanted oxygen (SIMOX) substrates is presented. Metal oxide semiconductor capacitors fabricated on the oxide are synthesized by SIMOX technique and evaluated by C–V, I–V and deep level transient spectroscopy (DLTS) techniques. A shift of flat-band voltage to negative values was observed, denoting the presence of a high density of positive charges into the oxide. They are mainly due to the large concentration of E′ centers. The concentration of interface states was high enough (1012 cm−2 eV−1) compared to that of thermal oxides and to govern the generation-recombination mechanisms at the interface. The activation energy of GR mechanism is very close to the half of Si energy gap. This mechanism affects the temperature formation of the inversion layer. The hold-off time of buried oxide capacitors was obtained by DLTS generation spectra analysis. Oxide charge instability was detected after stress under a relatively low electric field at 450 K. The generation-recombination mechanism was changed after stress, affecting also the hold-off time.