Effect of Post-annealing Processes on Filamentary-Based Resistive Switching Mechanism of Chromium Oxide Thin Films

Abstract

The interrelation between microstructure of chromium oxide films (CrOx) and formation of silver (Ag) filament in Ag/CrOx/Pt devices has been investigated at various annealing temperatures. It is revealed that Cr2O3 phase is dominant at high annealing temperatures and different microstructures of the CrOx films exhibit different resistance switching characteristics. As-deposited CrOx films with amorphous structure show highly reliable and reproducible resistance switching due to an easy formation of thin Ag filaments. 300A degrees C-annealed CrOx films with denser structure exhibit a fluctuating switching characteristics, relating to negative differential resistance (NDR) effect, in the first several tens of switching cycles, followed by a stable switching characteristics. On the contrary, the resistance switching is not observed in 500A degrees C-annealed CrOx films due to presence of voids or pinholes created at high annealing temperature. The roles of NDR effect and voids/pinholes on resistance switching characteristics of CrOx thin films are also discussed.