Paramagnetic Point Defects in Amorphous Thin Films of SiO2 and Si3 N 4: Updates and Additions

Recent research on point defects in thin films of silicon dioxide, silicon nitride, and silicon oxynitride on Si is presented and reviewed. In , it now clear that no one type of E' center is the sole source of radiation‐induced positive charge; hydrogenous moieties or other types of E' are proposed. Molecular orbital theory and easy passivation of E' by suggest that released H might depassivate interface sites. A charged center has been seen in Cl‐free SIMOX (separation by implantation of oxygen) and thermal oxide films, and it is reassigned to an electron delocalized over four units around a fifth Si. In , a new model for the amphoteric charging of moieties is based on local shifts in defect energy with respect to the Fermi level, arising from nonuniform composition; it does not assume negative U electron correlation. A new defect has been identified, with dangling orbital on a two‐coordinated N atom bonded to another N. Silicon oxynitride defects are briefly presented.