ELECTRICAL-PROPERTIES OF BURIED OXIDE-SILICON INTERFACE

A systematic approach of the origin of the generation-recombination me chanism (GR) at the back interface of buried oxide in separation by im planted oxygen (SIMOX) substrates is presented. Metal oxide semiconduc tor capacitors fabricated on the oxide are synthesized by SIMOX techni que and evaluated by C-V, I-V and deep level transient spectroscopy (D LTS) techniques. A shift of flat-band voltage to negative values was o bserved, denoting the presence of a high density of positive charges i nto the oxide. They are mainly due to the large concentration of E' ce nters. The concentration of interface states was high enough (10(12) c m(-2)eV(-1)) compared to that of thermal oxides and to govern the gene ration-recombination mechanisms at the interface. The activation energ y of GR mechanism is very close to the half of Si energy gap. This mec hanism affects the temperature formation of the inversion layer. The h old-off time of buried oxide capacitors was obtained by DLTS generatio n spectra analysis. Oxide charge instability was detected after stress under a relatively low electric field at 450 K. The generation-recomb ination mechanism was changed after stress, affecting also the hold-of f time. (C) 1996 American Institute of Physics.