An Improved Structure Enabling Hole Erase Operation When Using an IGZO Channel in a 3D NAND Flash Structure to Which COP (Cell-On-Peri) Structure Is Applied

Abstract

In this paper, we proposed an improved (Indum-Galum-Zinc-Oxide) IGZO-Filler (IF) structure that can be used in a Cell-On-Peri (COP) structure by improving the excellent erase performance of the IGZO-Pillar (IP) structure. The IP structure mentioned above is a structure that we announced in a previous study, and this structure overcomes the poor hole carrier characteristics of IGZO when the IGZO channel was used in the early 3D NAND Flash structure and enables hole erase operation. The proposed structure showed that, despite the very poor hole carrier characteristics of IGZO, hole erase operation is sufficiently possible even if only a few hole carriers exist in a thin pillar of 5 nm thickness. Simulation results show that the proposed structure exhibits a fast erase rate of 100 μs, similar to that of the existing structure, while maintaining the low leakage current properties inherent in the IGZO material. Therefore, the proposed structure is expected to maintain the excellent characteristics of the IGZO channel even in the 3D NAND Flash of the COP structure, which enables erasure operation while overcoming leakage current and temperature stability problems of existing polysilicon channels.