Improved endurance in ultrathin Al2O3 film with a reactive Ti layer based resistive memory

A 3-nm-thick Al2O3 based resistive memory with a Ti layer was prepared in this work. The Ti/HfOx devices with the same thickness were also fabricated for comparison. The oxygen gettering of Ti form Al2O3 is lower than that from HfOx. The Al2O3 devices with strong dielectric strength exhibit tight distribution of initial resistance state and high resistance state. The low resistance state, SET and RESET voltage of the devices seems insensitive to the dielectric film. Without an ideal current limiter, high forming voltage (VF) leads to the Al2O3 device with poor endurance (<100 cycles). Reduction of current overshoot by an external resistor of 800 Ω during forming process, the endurance of the memory device can be improved and increase up to 104 cycles. The current overshoot and VF in the Al2O3 device with high operational temperature during forming step can be also suppressed.

► A 3-nm-thick Al2O3 based resistive memory with a Ti layer was prepared. ► The Al2O3 exhibit tight distribution of initial state and high resistance state. ► With an external resistor during forming step, endurance of Al2O3 are improved. ► Current overshoot in Al2O3 with high temperature during forming is suppressed.