Yasunari Hosoi

TiO2 anatase nanolayer on TiN thin film exhibiting high-speed bipolar resistive switching

The surface oxidized layer of a TiN barrier metal thin film grown on a Pt electrode was used as a resistive switching material. The fabricated memory cell shows bipolar resistive switching on a nanosecond order. A TiO2 anatase layer of about 2.5nm thick on TiN thin film was characterized by high-resolution scanning transmission electron microscopy. The results suggested that the high-speed resistive change was derived from the Mott transition in the TiO2 anatase nanolayer, and the obtained results could relate to the formation of filament paths previously reported in binary transition metal oxide thin films exhibiting resistive switching.

High-Speed Resistive Switching of TiO2/TiN Nano-Crystalline Thin Film

High-speed resistive switching was observed in a TiO2/TiN nano-crystalline thin film sandwiched between platinum electrodes. A low resistance state was achieved by applying a single negative 2.0-V amplitude 20-ns wide electric pulse, while a high resistance state was achieved by applying a single positive 2.2-V amplitude 30-ns wide electric pulse. So-called forming process, heating bit material by current flow to form conductive filament path before the resistive switching operation was not required. There was an approximately 40,000% increase in resistive change that was repeatedly obtained in the system.