Collective motion of conducting filaments in Pt/n-type TiO ₂/p-type NiO/Pt stacked resistance switching memory

Filamentary resistance switching (RS) is one of the more obvious and useful phenomena in the family of RS mechanisms. In filamentary RS, the long reset switching time and substantially large power consumption are the critical obstacles for microelectronic applications. In this study, an innovative solution to overcome this reset problem is suggested by stacking n-type TiO ₂ and p-type NiO films. Interestingly, in this stacked structure, the region where filament rupture and rejuvenation occurs could be arbitrarily controlled to be at any location between the interface with the metal electrode and the TiO₂ / NiO interface by using an appropriate switching sequence. This collective motion behavior of conducting filaments can be practically used to reduce reset switching time from ∼100 μs to ∼150 ns, with an extremely high off/on resistance ratio of ∼ 10⁶.