Effects of electrode polarity on filament ruptures during unipolar resistance switchings

It has been argued that in unipolar resistance switching of Pt/TiO2/Pt capacitors, conducting filaments should propagate from the cathode interface, and the rupture and recovery of the filaments should occur near the anode interface [Kim et al., Appl. Phys. Lett. 91 (2007) 012907]. We investigated whether this “anode-interface localized filamentary mechanism” holds for Pt/NiO/Pt capacitors. We examined how the electrode polarity affects the rupturing of the conducting filaments in unipolar resistance switching by performing resistance switching measurements on 246 NiO capacitors. We found some dependencies on electrode polarity; however, they were not consistent with the anode-interface localized filamentary mechanism. We also found that Joule heating affects the rupturing process, suggesting that the weakest link of conducting filaments in NiO thin films plays an important role during the rupturing process.