Improvement of resistive switching uniformity for TiO2-based memristive devices by introducing a thin HfO2 layer

Memristive devices have attracted considerable attention as a promising candidate for the next generation nonvolatile random access memory and unconventional computing. One obstacle for wide applications of these devices is their performance variation from device to device and from cycle to cycle. Here, the authors report that by introducing a thin HfO2 layer into the Pt/TiO2/Pt device geometry, the cycle-to-cycle uniformity of the programing voltages and the resistance states are greatly improved. The programing voltages are distributed in much narrower ranges. The uniformities of low-resistance state resistance and high-resistance state resistance were improved by 25 and 20 times, respectively. It is believed that the extra layer of HfO2 has led to fewer potential conducting filaments in the bilayer devices, contributing to the significant improvement in switching uniformity. (C) 2013 American Vacuum Society.