The Atomic Switch

An atomic switch is a nanoionic device that controls the diffusion of metal ions and their reduction/oxidation processes in the switching operation to form/annihilate a metal atomic bridge, which is a conductive path between two electrodes in an ON-state. Since metal atoms can provide a highly conductive channel even if their size is in the nanometer scale, atomic switches may enable downscaling to smaller than the 11-nm technology node. Two-terminal atomic switches have the potential for use in memories and programmable switches. Three-terminal atomic switches, where the formation/annihilation of a metal atomic bridge between a source electrode and a drain electrode are controlled by a third (gate) electrode, work as nonvolatile transistors. Recent development of two-terminal atomic switches that use a metal oxide as the ionic conductive material, in which a metal atomic bridge is formed, has enabled the integration of atomic switches with complementary metal-oxide-semiconductor (CMOS) devices. Also introduced are the novel characteristics of atomic switches, such as their small size, low power consumption, low ON-resistance, nonvolatility, and learning abilities.