Filament localization and resistive switching power reduction in VO_x via focused ion irradiation

Numerous materials exhibit resistive switching, a useful property which lends well to implementation of bioinspired electronic devices, notably artificial neurons and synapses for neuromorphic computing. In many systems, this effect occurs through the percolation of conducting filaments across an insulating matrix. Often, the location and switching parameters are impacted by inherent material defects, which poses a serious challenge for scalability of neuromorphic circuits. By selectively engineering defects using a focused ion beam, we report a novel method of locally tuning a material's electronic properties (i.e. conductivity and metal-insulator transition temperature) and by extension, controlling the location and shape of the conducting filament. In addition to confining the filament to the irradiated region, we observe a greater than 3 orders of magnitude reduction in switching power. Our work demonstrates that local ion irradiation is an efficient tool for fine-tuning resistive switching properties. This offers promising avenues for new energy-efficient biomimetic circuitry.