Doping profile modification approach of the optimization of HfO x based resistive switching device by inserting AlO x layer

HfO x based resistive switching devices with thin AlO x layer inserted between HfO x and TiN top electrode (TE) and Pt bottom electrode (BE) were fabricated respectively. Both devices show robust bipolar resistive switching phenomenon. Experimental result reveals that TiN/AlO x /HfO x /Pt device with appropriately thick HfO x film shows significant enhancement in performance as compared with other samples, having lower voltage and excellent uniformity. The role of inserted AlO x layer and thickness of HfO x film on resistive switching properties are discussed and clarified through comparative experiments, which is considered to be a doping effect. The experimental result is consistent with the model where resistive switching happens near TiN top electrode (TE) due to partial rupture and reconstruction of conducting filaments (CFs) assisted by the doping. The different doping profiles near top electrode of the samples were confirmed by XPS depth analysis. This work provides detailed information about the optimization of HfO x based resistive switching device by a doping profile modification approach.