An innovative 3D-NAND design based on light-emitting cell for high reliability and low power consumption

Abstract

The advancements in 3D-NAND technology have significantly increased the number of vertically stacked cells, which are controlled via word lines (WLs), enabling higher cell density and reducing costs. However, the increase in vertical cell layers has also introduced challenges such as higher power consumption and diminished current levels, both of which compromise the reliability of memory cells. At the same time, the demand for high cell reliability and low power consumption has been growing, driven by the expanding needs of storage applications in big data and cloud services. In this study, we propose an optically readable light-emitting memory (LEM) as a unit cell within 3D-NAND architecture. This innovative design exhibits both effective memory performance and light-emitting capabilities. Unlike conventional memory cells that require all WLs to be biased during read operation, the LEM requires only a read bias on the selected WL to detect the light intensity, which directly correlates with the stored data state. By applying voltage only to the selected WL, power consumption is reduced by approximately 45%. In addition, issues such as read disturbances and low cell currents that affect cell reliability are effectively mitigated, resulting in an expected improvement in the read window.