Effects of Poly-Si Grain Boundary on Retention Characteristics under Cross-Temperature Conditions in 3-D NAND Flash Memory.

Electrical characteristics with various program temperatures () in three-dimensional (3-D) NAND flash memory are investigated. The cross-temperature conditions of the up to 120 °C and the read temperature () at 30 °C are used to analyze the influence of grain boundaries (GB) on the bit line current () and threshold voltage (). The shift in the E-P-E pattern is successfully decomposed into the charge loss (Δ) component and the poly-Si GB (Δ) component. The extracted Δ increases at higher due to the reduced GB potential barrier. Additionally, the Δ is evaluated using the Technology Computer Aided Design (TCAD) simulation, depending on the GB position () and the bit line voltage ().