EXCESS-SI RELATED DEFECT CENTERS IN BURIED SIO2 THIN-FILMS

Using electron paramagnetic resonance (EPR) and capacitance-voltage me asurements we have investigated the role of excess-silicon related def ect centers as charge traps in separation by the implantation of oxyge n materials. Three types of EPR-active centers were investigated: oxyg en vacancy Egamma' centers (O3=Si. +Si=O3), delocalized Edelta' center s, and D centers (Si3=Si.). It was found that all of these paramagneti c centers are created by selective hole injection, and are reasonably ascribed as positively charged when paramagnetic. These results provid e the first experimental evidence for (1) the charge state of the Edel ta' center, and (2) that the D center is an electrically active point defect in these materials.