Non-Volatile Resistive Memory Switching in Pulsed Laser Deposited Rare-Earth Gallate-GdGaO3 Thin Films

Abstract

Pulsed laser deposited amorphous GdGaO3 (GGO) thin films were investigated to explore their resistive switching (RS) behaviour. Pt/GGO/Pt memory cells showed a stable resistance ratio of ~104 between low resistance state (LRS) and high resistance state (HRS) and non-overlapping switching voltages (set voltage, VON ~1.2˗1.4 V and reset voltage, VOFF ~0.6˗0.8 V) with a small variation of about ± 5˗10% in each. To confirm the reliability of the memory cell, cyclic endurance tests up to 80 set/reset cycles and data retention checks up to 103 seconds were performed. Unipolar RS mechanism in Pt/GGO/Pt memory cell was explained by a conductive filament (thermo-chemical) model, where the change in resistance state (LRS↔HRS) was found to occur due to the formation/rupture of conductive filaments consisting of metallic Gd-atoms and oxygen vacancies. The charge transport mechanisms in LRS and HRS were found to be compatible with Ohmic conduction and space–charge limited current, respectively.