Focus ion beam-induced mechanical stress switching in an ultra-fast resistive switching device

The Mo/Si3N4:Pt/Pt nanometallic resistive switching devices with ultra-fast write/erase speed (<50 ns) were fabricated. Other than conventional electrical switching, a mechanical stress-induced switching was demonstrated. Such mechanical stress was provided by momentum transfer of 30 keV Ga+ ions in a focus ion beam system, enabling a one-way high resistance state (HRS) to low resistance state (LRS) transition. The capability of mechanical stress switching provides evidence that electron trapping/detrapping mechanism is responsible for nanometallic resistive switching. It was further demonstrated that HRS (trapping state) is a meta-stable state, while LRS (detrapping state) is a stable state. Strong mechanical stress facilitates local bond distortion in dielectric films and thus lowers the energy barrier between HRS and LRS, eventually leading to a barrier-less state transition. A quantitative model based on stress-mediated parallel conduction paths were established to provide a more accurate description of the resistive switching devices.