Nano-analytical investigation of the forming process in an HfO2-based resistive switching memory

Gauthier Lefevre (1, 2) , Tristan Dewolf (2) , Nicolas Guillaume (1, 2) , Serge Blonkowski (2) , Christelle Charpin-Nicolle (2) , Eric Jalaguier (2) , Etienne Nowak (2) , Nicolas Bernier (2) , Tom Blomberg , Marko Tuominen , Hessel Sprey , Guillaume Audoit (2) , Sylvie Schamm-Chardon (3)

1 LTM - Laboratoire des technologies de la microélectronique
2 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
3 CEMES-MEM - Matériaux et dispositifs pour l'Electronique et le Magnétisme

Metal oxide-based resistive random access memory devices are highly attractive candidates for next-generation nonvolatile memories, but the resistive switching phenomena remain poorly understood. This article focuses on the microscopic understanding of the initial forming step, which is decisive for the switching process. The integrated resistive switching memory effect in Ti/HfO2/TiWN metal insulator metal structures is studied. After forming, transmission electron microscopy investigations pointed out the presence of a funnel-shaped region, in the ON state of the cell, where slightly oxidized Ti (TiOx) was present within HfO2 dielectric. Modeling of the measured ON state conductance of the cell with the semi-classical approximation is consistent with a conductive nanometric TiOx filament (or a sum of sub-nanometric TiOx filaments) present in the funnel-shaped region. The conductive area is likely formed by diffusion after the dielectric breakdown

Mots clés: Resistive switching memories; Electron energy loss spectroscopy; Transmission electron microscopy; Current-voltage characteristics; Atomic layer deposition

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Gauthier Lefevre, Tristan Dewolf, Nicolas Guillaume, Serge Blonkowski, Christelle Charpin-Nicolle, et al.. Nano-analytical investigation of the forming process in an HfO2-based resistive switching memory. Journal of Applied Physics, 2021, 130 (24), pp.244501. ⟨10.1063/5.0072343⟩. ⟨hal-03720298⟩