PROPERTIES OF BONDED HYDROGEN IN HYDROGENATED AMORPHOUS-SILICON AND OTHER HYDROGENATED AMORPHOUS-SILICON ALLOYS

This paper discusses bonding configurations of hydrogen atoms (H) in a morphous silicon and amorphous-silicon-based alloys. Recent experiment s combined with theoretical calculations have identified two new aspec ts of bonded H that have not previously been addressed: (i) the format ion of H bonds between H atoms on Si-H groups and electronegative atom s or groups such as O atoms or NH groups; and (ii) an inherent metasta bility of H-bonded clusters as driven by the trapping of charged carri ers. Both of these are shown to play important roles in (i) a photo-in duced defect metastability such as the Staebler-Wronski effect, and (i i) hydrogen evolution from amorphous silicon nitrides. Finally, the co ncepts developed for a-Si:H alloys apply equally well to defect metast ability at Si-SiO2 interfaces as in metal-oxide-semiconductor devices including insulated-gate field-effect transistors.