Effects of HfO2 trapping layer in Gd2O3 nanocrystal nonvolatile memory with multi-tunneling layers

Recently, nanocrystal (NC) memory such as gadolinium oxide NC (Gd₂O₃-NC) memory performed by the band-gap offset of a crystallized Gd₂O₃-NC dots surrounded by the amorphous Gd₂O₃ dielectrics has been proposed. The crystallization temperature was optimized and the excellent memory properties were obtained. In addition, to improve the programming/erasing (P/E) and retention characteristics of future nonvolatile memory, the BE-SONOS with SiO₂/SiN/ SiO₂ (ONO) tunneling layer has been proposed due to the suitable band engineering and large physical thickness. In this paper, the novel Gd₂O₃-NC memory with HfO₂ charge trapping layer was investigated and multi-tunneling layer (Al₂O₃/IL-SiO₂) was applied to further improve the performance. The charge storage characteristic was related to the charge trapping phenomenon of HfO₂ layer.