Evaluation of gadolinium oxide as a blocking layer of charge-trap flash memory cell

Abstract

A rare-earth oxide, Gd(2)O(3), is evaluated for the application of the blocking layer in polysilicon-oxide-silicon nitride-oxide-silicon-type flash memory cell devices because of its high conduction-band offset and reasonably large kappa value. In a Gd(2)O(3)/Si(3)N(4)/SiO(2) dielectric stack, a monoclinic-structured Gd(2)O(3) shows the advantage of faster program/erase speed with comparable charge retention when compared to a conventional Al(2)O(3) blocking layer. Such performance makes Gd(2)O(3) a promising high-kappa material for the blocking layer in charge-trap flash memory devices. (C) 2008 The Electrochemical Society.