Experimental Extraction of the Charge Centroid of Holes Trapped in Metal–Oxide–Nitride–Oxide–Semiconductor Memories

Abstract

To obtain the charge centroid of holes trapped in the silicon nitride film in the metal-oxide-nitride-oxide-silicon (MONOS)-type memory, we proposed a method based on the analysis of Fowler-Nordheim (F-N) tunneling current through the blocking oxide film. The charge centroid and the density of holes captured by empty trap centers in the silicon nitride film at high gate voltages were determined by means of the proposed method. The charge centroid of holes trapped in the silicon nitride film moved from the middle of the film toward the blocking oxide-silicon nitride interface as the flat-band voltage shift increased. Finally, the charge centroid reached 2.5 nm from the interface. We also have shown that the density of trapped holes was saturated at 1.0×1013 holes/cm2 after a sufficient number of holes were injected. The proposed method is useful to analyze the charge trapping phenomena in MONOS devices.