Study of the bipolar resistive-switching behaviors in Pt/GdO_x/TaN_x structure for RRAM application

摘要

The bipolar resistive switching (RS) behaviors in Pt (top)/ GdO_x/TaN_x (bottom) memory cells were investigated systematically for RRAM applications. Compared to that of the memory cells in Pt/Gd(VPt structure showing unipolar switching behaviors, the memory cells in Pt/GdO_x/TaN_x structure with bipolar switching behaviors show better switching properties, such as better switching reliability, enhanced cycling endurance, improved low resistive state value and more uniform RS parameters. The composition and chemical bonding states of the prepared GdO_x and TaN_x films were analyzed by X-ray photoelectron spectroscopy to elucidate the underlying resistive switching mechanisms for Pt/GdO_x/TaN_x structures. The results show that both the oxygen vacancies in the GdO_x film and the interfacial TaON layer formed between the dielectric GdO_x film and the TaN_x bottom electrode play important roles in the RS performance improvement.