Fully BEOL compatible TaOx-based selector with high uniformity and robust performance

We report a novel TaOx-based selector with trapezoidal band structure, formed by rapid thermal annealing in O₂ plasma. Salient features were successfully achieved, such as high current density (1MA/cm²), high selectivity (5×10⁴), low off-state current (~10 pA), robust endurance (>10¹⁰), self-compliance and excellent uniformity. The device is composed of fully CMOS-compatible materials and has no thermal budget compatibility concerns. Furthermore, the selector was fabricated in 1kb crossbar array and the integrated 1S1R device shows high nonlinearity in low resistance state (LRS), which is quite effective to solve the sneaking current issue. The demonstrated high performance selector device here shows high potential on manufacturing large scale crossbar array.