Improved ON-State Reliability of Atom Switch Using Alloy Electrodes

Cu-alloy active-electrode coupled with Ru-alloy inert electrode is proposed to improve the ON-state reliability of nonvolatile Cu atom switch. The high rupture temperature (T_r > 400 °C) of the nanometer-scale Cu bridge with high thermal resistance (R_th) is realized by the Cu(AlTi)-alloy without increasing programming current. The anti-Cu diffusive Ru(Ta) alloy contributes to improve the retention of the ON-state at 150 °C and endurance to > 10⁴ cycles. The metallurgical prescription on the electrodes is a key to improve the stability of the nanometer-scale conducting bridge while keeping the switching power low.