Impact of High-k Bandgap Engineering on V-NAND Cell Performance

We propose an optimized high-k bandgap engineering structure to meet the demands of high-capacity vertical NAND (V-NAND). Simulation results show that the HfO₂/Si₃N₄/Oxide (H/N/O) structure exhibits superior program/erase (P/E) characteristics compared to the conventional single structure. Specifically, the programming speed increases by 84%, the erase speed improves by 155%, and the cell current is enhanced by 13%. These improvements are attributed to the reduced equivalent oxide thickness (EOT), optimized tunneling barrier, and improved charge retention properties. Additionally, the H/N/O structure exhibits the highest self-boosting efficiency. Finally, through simulations and analysis, we present an optimized tunneling oxide bandgap engineering strategy. These findings provide important insights for future V-NAND development, ensuring excellent reliability and efficiency at higher densities.