Effect of Al doping on the retention behavior of HfO2 resistive switching memories

Display Omitted The retention behavior of HfO2-based memories is analyzed as a function of Al doping.The high resistance state reveals two main mechanisms of data retention degradation.Gradual resistance lowering increases with Al doping due to enhanced diffusion.High Al concentrations induce an increase of sharp resistance losses.Tailoring the Al concentration allows to limit an excessive retention degradation. The retention behavior of HfO2-based resistive switching memory cells (RRAM) is characterized as a function of Al doping concentration, which was previously reported to be a viable method for the improvement of the switching uniformity. While the low resistance state (LRS) does not exhibit any major variation up to 106s for all the tested devices, two retention loss mechanisms can be identified for the high resistance state (HRS). The main HRS trend follows a temperature-activated gradual decrease of the resistance, which also depends on the doping concentration. In addition, tail bits of the population distribution show a very fast retention loss process that strongly depends on the doping concentration.