Analysis of Program Speed Characteristics Having Non-ideal Channel Profile in 3D NAND Flash Memory

This study presents an in-depth investigation of the channel profile and program speed of non-ideal vertical 3-dimensional (3D) NAND Flash Memory. Using 3D technology computer-aided design (TCAD) simulations, the channel profiles were transformed into oxide-nitride-oxide (O/N/O) structures, providing insights into their impact on the device performance. Step-by-step programming was conducted for the initial state of each channel profile. Upon applying the programmed voltage, variations in the E-field of the tunneling oxide were observed based on the channel profile. Consequently, the concentration of the trapped electrons in the nitride, depending on the channel profile, was identified. Therefore, this study analyzed the influence of E-field differences due to channel profiles on the program speed and investigated vulnerable structures.