Nonvolatile floating gate memory characteristics of Sb2Te–SiO2 nanocomposite thin films

Abstract

Nonvolatile floating gate memory (NFGM) device composed of Sb2Te nanocrystals (NCs) as the charge-storage traps embedded in SiO2 matrix was prepared by the target-attachment sputtering method at various nitrogen (N2) incorporation conditions. Via post annealing at 450°C in ambient air, the sample prepared at the condition N2/Ar=0.1 exhibited a maximum memory window (ΔVFB) shift=4.4V and charge density=4.2×1012cm−2 under ±7V gate voltage sweep. N2 incorporation not only reduced the Sb2Te NC size to about 5nm, but also suppressed the oxygen defects and antimony oxides in the sample. Feasibility of the Sb2Te chalcogenide NCs to NFGM fabrication with the simplified process and relatively low annealing temperature is demonstrated.