Resistance switching variability in HfO2-based memory structures with different electrodes

Thomas Cabout (1, 2) , Julien Buckley (2) , Carlo Cagli (2) , Vincent Jousseaume (2) , Jean-François Nodin (2) , Barbara de Salvo (2) , Marc Bocquet (1) , Christophe Muller (1)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information

This paper deals with the effect of platinum or titanium-based electrodes on resistive switching characteristics and electrical performances of HfO2-based memory elements. Capacitor-like Pt/HfO2(10nm)/Pt and Ti/HfO2(10nm)/TiN structures were fabricated on top of a tungsten pillar bottom electrode and integrated in-between two interconnect metal lines. Initially, quasi-static measurements were performed to study the influence of electrode nature on forming, set and reset operations and their corresponding switching parameters. Memory elements with top and bottom Pt electrodes exhibited a non-polar behavior with sharp decrease of current during reset operation while cells integrating Ti-based electrodes showed a bipolar switching behavior, with a progressive reset. Then, statistical distribution of switching parameters (voltage and resistance) were extracted from data obtained on hundreds of memory devices. Even if the resistance in the low resistive state (LRS) and the reset voltage were found to be comparable for both kinds of electrodes. On the other hand, the progressive reset operation observed on samples with Ti-based electrodes led to a lower variability of resistance in high resistive state (HRS) and subsequently of set voltage. In addition Ti-based electrodes enabled gaining: (i) lower forming and set voltages with significantly narrower cell-to-cell distributions; (ii) a better data retention (10 years at 65°C instead of 10 years at 50°C for Pt electrodes); (iii) satisfactory dynamic performances with lower set and reset voltages for ramp speed ranging from 10-2 to 107 V/s.

Mots clés: switching memory; HfO2 switchable layer; titanium-based electrodes; variability

Domaines: Micro et nanotechnologies/Microélectronique

Thomas Cabout, Julien Buckley, Carlo Cagli, Vincent Jousseaume, Jean-François Nodin, et al.. Resistance switching variability in HfO2-based memory structures with different electrodes. EMRS Spring Meeting 2012, May 2012, Strasbourg France. ⟨hal-01738395⟩