CBRAM devices based on a nanotube chalcogenide glass structure

CBRAM nano-ionic devices are emerging as a competitive technology solution for transistor free memory, offering low power consumption, fast switching, and non-volatility. However, due to the process by which switching is achieved in these devices, namely stochastic growth of a conductive filament bridging the two electrodes within the amorphous material between the electrodes, they suffer from reliability problems. In this work we present devices built with a nanotube structure of chalcogenide glasses to confine the growing conductive bridge. This structure is found to greatly improve device reliability and switching speed. Furthermore, the technology does not involve additional steps, is cost-effective, and is fully compatible with conventional CMOS technology. We have verified the process of conductive bridge growth with scanning electron microscopy and atom force microscopy and characterized the devices in terms of their current–voltage characteristics, memory window, endurance, and retention, all of which show excellent parameters. Their performance stability is also demonstrated at 130 °C, while multilevel switching is established by application of a variety of compliance currents.