Performance of a MOHOS-type Memory Using HfO₂ nanoparticles as Charge Trapping Layer and Ultra-Thin Tunneling Oxide Thickness

Abstract

In this work, we use HfO 2 nanoparticles (np-HfO 2 , embedded in a spin-on glass SOG oxide matrix) as charge trapping layer (CTL) in Metal/Oxide/High-κ/Oxide/Silicon (MOHOS)-type non-volatile memory structures. By depositing the same CTL on an ultra-thin layer of chemical oxide (SiOx ≤ 2 nm), a distinctive trade-off is observed in both writing/erasing and data retention time characteristics when different thicknesses are used for the tunneling oxide. Specifically, better writing/erasing times are obtained while the data retention characteristics worsen when the tunneling oxide thickness decreases to less than 2 nm. The best memory performance is obtained for a CTL (∼120nm, based on np-HfO 2 ) deposited on a tunneling oxide of 1.5nm < SiOx < 2nm.