Resistive switching in a LaMnO3 + δ/TiN memory cell investigated by operando hard X-ray photoelectron spectroscopy

Abstract

Transition metal oxides are promising candidates in the development of valence change memories thanks to their ability to present the valence change mechanism. The resistive switching mechanism of TiN/LaMnO3 + δ (LMO)/Pt devices was investigated by operando hard X-ray photoelectron spectroscopy after careful in situ electrical characterization. The results presented here highlight the oxygen exchange process at the TiN/LMO interface. The active TiN top electrode acts as an oxygen getter, pumping O2- anions that are attracted by the positive bias and repelling them under negative bias. This drift of charged defects is correlated with variations of the interfacial resistance. Our results confirm the critical role of the TiN/LMO interface and oxygen drift in the resistive switching behavior of such devices.