Operando diagnostic detection of interfacial oxygen ‘breathing’ of resistive random access memory by bulk-sensitive hard X-ray photoelectron spectroscopy

The HfO2-based resistive random access memory (RRAM) is one of the most promising candidatesfor non-volatile memory applications. The detection and examination of the dynamic behavior ofoxygen ions/vacancies are crucial to deeply understand the microscopic physical nature of theresistive switching (RS) behavior. By using synchrotron radiation based, non-destructive and bulksensitivehard X-ray photoelectron spectroscopy (HAXPES), we demonstrate an operando diagnosticdetection of the oxygen ‘breathing’ behavior at the oxide/metal interface, namely, oxygen migrationbetween HfO2 and TiN during different RS periods. The results highlight the significance ofoxide/metal interfaces in RRAM, even in filament-type devices