Cu BEOL compatible selector with high selectivity (>107), extremely low off-current (?pA) and high endurance (>1010)

Selector with high nonlinearity and low leakage current is critical to solve the sneaking current issue in crossbar memory array. In this work, we present a high performance Cu BEOL compatible threshold switching (TS) selector with several outstanding features, such as high nonlinearity (~10⁷), ultra-low off-state leakage current (~pA), robust endurance (> 10¹⁰), and sufficient on-state current density (~1 MA/cm²). The observed threshold switching is resulted from the spontaneously rupture of conductive filament in doped HfO₂ material. By introducing a tunneling layer in series with the TS layer, the leakage current of the selector is dramatically reduced by more than 5 orders of magnitude. The array level benchmark of this TS selector qualifies its promising potential for 3D storage application.