Multiple memory states in resistive switching devices through controlled size and orientation of the conductive filament

Abstract

Multilevel operation in resistive switching memory (RRAM) based on HfO x is demonstrated through variable sizes and orientations of the conductive filament. Memory states with the same resistance, but opposite orientation of defects, display a different response to an applied read voltage, therefore allowing an improvement of the information stored in each physical cell. The multilevel scheme allows a 50% increase (from 2 to 3 bits) of the stored information. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.