Interface traps at midgap during defect transformation in (100) Si/SiO2

Abstract

The interface traps generated by ionizing radiation or hot-electron injection undergo continuous changes with time after the damaging source is turned off. This letter focuses on the interfacial defect transformation process in (100) Si/SiO2, in which a large portion of the interface trap peak in the upper half of the Si band gap gradually converts into a second peak in the lower half of the band gap. It will be shown that, when the interfacial defect transformation process dominates, the interface trap density at midgap does not change with time, despite the fact that other portions of the interface traps undergo drastic changes. The time-dependent behavior of the midgap density provides a convenient indicator to determine whether the dominant process is defect transformation, annealing (the midgap density decreases with time), or latent generation (the midgap density increases with time).