Three-fold improved set-voltage variability of a Cu atom switch with a split electrode for very-large-scale integration

We propose a self-selected smallest set-voltage cell (4S-cell) to realize three-fold improvement of the set-voltage (Vset) variability of Cu atom switches. In the cell, switches are connected in parallel and the switch with the smallest Vset is automatically selected, resulting in smaller Vset variability. For practical application, a split-electrode structure is introduced. The 4S-cells of 2-in-1 by using a split electrode without any increase in cell area reduced the 6σ of Vset with an equivalent σVset of 28 mV. The developed 4S-cell enables very-large-scale integration of atom switches for embedded memory and routing switch applications used in ultra-low-power systems-on-chips for wireless sensor node applications.