A Robust and Low-Power Bismuth Doped Tin Oxide Memristor Derived from Coaxial Conductive Filaments

Memristor, processing data storage and logic operation all-in-one, is an advanced configuration for next generation computer. In this work, a bismuth doped tin oxide (Bi:SnO₂ ) memristor with ITO/Bi:SnO₂ /TiN structure has been fabricated. Observing from transmission electron microscope (TEM) for the Bi:SnO₂ device, it is found that the bismuth atoms surround the surface of SnO₂ crystals to form the coaxial Bi conductive filament. The self-compliance current, switching voltage and operating current of Bi:SnO₂ memristor are remarkably smaller than that of ITO/SnO₂ /TiN device. With the content of 4.8% Bi doping, the SET operating power of doped device is 16 µW for ITO/Bi:SnO₂ /TiN memory cell of 0.4 × 0.4 µm² , which is cut down by two orders of magnitude. Hence, the findings in this study suggest that Bi:SnO₂ memristors hold significant potential for application in low power memory and broadening the understanding of existing resistive switching (RS) mechanism.