Forming mechanism of Te-based conductive-bridge memories

Munique Kazar Mendes (1, 2) , Eugenie Martinez (1, 2) , A Marty (1, 2) , Marc Veillerot (1, 2) , Y. Yamashita (3) , Rémy Gassilloud (1, 2) , M Bernard (1, 2) , Olivier Renault (1, 2) , N. Barrett (4)

1 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
2 UGA [2016-2019] - Université Grenoble Alpes [2016-2019]
3 Advanced Electronic Materials Center [NIMS]
4 LENSIS - Laboratoire d'Etude des NanoStructures et Imagerie de Surface

We investigated origins of the resistivity change during the forming of ZrTe/Al$_2$O$_3$ based conductive-bridge resistive random access memories. Non-destructive hard X-ray photoelectron spectroscopy was used to investigate redox processes with sufficient depth sensitivity. Results highlighted the reduction of alumina correlated to the oxidation of zirconium at the interface between the solid electrolyte and the active electrode. In addition the resistance switching caused a decrease of Zr-Te bonds and an increase of elemental Te showing an enrichment of tellurium at the ZrTe/Al$_2$O$_3$ interface. XPS depth profiling using argon clusters ion beam confirmed the oxygen diffusion towards the top electrode. A four-layer capacitor model showed an increase of both the ZrO$_2$ and AlO$_x$ interfacial layers, confirming the redox process located at the ZrTe/Al$_2$O$_3$ interface. Oxygen vacancies created in the alumina help the filament formation by acting as preferential conductive paths. This study provides a first direct evidence of the physico-chemical phenomena involved in resistive switching of such devices.

Keywords: RRAM; CBRAM; Oxygen scavenging; Interface chemistry; HAXPES

Domains: Physics [physics]

Munique Kazar Mendes, Eugenie Martinez, A Marty, Marc Veillerot, Y. Yamashita, et al.. Forming mechanism of Te-based conductive-bridge memories. Applied Surface Science, In press, ⟨10.1016/j.apsusc.2017.07.187⟩. ⟨cea-01591636⟩