Understanding of the endurance failure in scaled HfO2-based 1T1R RRAM through vacancy mobility degradation

Bipolar switching transition metal-oxide (TMO) RRAM devices are intensively studied as possible non-volatile memory for 1x nm node. HfO₂ based stacks with excellent operation, good endurance and retention have been proposed [1, 2, 3], with demonstrated scalability down to <;10nm [3]. However, characterization of the reliability failure modes and understanding of the degradation mechanism is urgently needed, especially in the low operation current range relevant for practical application of RRAM devices. Although retention and endurance models in different TMO have been proposed [4, 5, 6], an in-depth understanding of endurance is still lacking for scaled HfO₂ RRAM in low current operation.