Effects of HfO<inf>2</inf> trapping layer in Gd<inf>2</inf>O<inf>3</inf> nanocrystal nonvolatile memory with multi-tunneling layers

Abstract

Recently, nanocrystal (NC) memory such as gadolinium oxide NC (Gd 2 O 3 -NC) memory performed by the band-gap offset of a crystallized Gd 2 O 3 -NC dots surrounded by the amorphous Gd 2 O 3 dielectrics has been proposed [1–2]. The crystallization temperature was optimized and the excellent memory properties were obtained [2]. In addition, to improve the programming/erasing (P/E) and retention characteristics of future nonvolatile memory, the BE-SONOS with SiO 2 /SiN/ SiO 2 (ONO) tunneling layer has been proposed due to the suitable band engineering and large physical thickness [3]. In this paper, the novel Gd 2 O 3 -NC memory with HfO 2 charge trapping layer was investigated and multi-tunneling layer (Al 2 O 3 /IL-SiO 2 ) was applied to further improve the performance. The charge storage characteristic was related to the charge trapping phenomenon of HfO 2 layer.