Cycling-Induced SET-Disturb Failure Time Degradation in a Resistive Switching Memory

A new degradation mode with respect to write-disturb failure time due to SET/RESET cycling in a tungsten oxide resistive random access memory is reported. In a crossbar array memory, we find that a write-disturb failure time in high resistance state reduces suddenly by several orders of magnitude after certain SET/RESET cycles. This abrupt degradation is believed due to the creation of a new soft breakdown path in a switching dielectric by cycling stress. Although a memory window still remains after the degradation, the occurrence probability of over-SET state increases significantly. This cycling-induced degradation mode imposes a serious constraint on the number of SET-disturb pulses and thus an endurance cycle number in a resistive switching memory.