Charge trap memory characteristics of AlOx shell-Al core nanoparticles embedded in HfO2 gate oxide matrix

Abstract

The memory behavior of natively oxidized AlOx shell-Al nanoparticles (NPs) in a metal oxide semiconductor (MOS) structure was investigated. Transmission electron microscopy images clearly demonstrate the formation of an AlOx shell (thicknesses of 1-1.5 nm), surrounding Al (sizes of 5-7 nm) core NPs in the MOS structure. Electrical measurements exhibited a memory window of 3.6 V, together with a promising charge retention time of about 10 years. A possible band model needed for enhanced retention characteristics was given by considering the electron/hole barrier width and the additional interface states through the AlOx shell as a method of tunneling barrier engineering.