Self-heating effects (SHEs) were investigated through simulations for 3-D V- NAND flash memory. The SHEs are varied by adjusting the thickness of the poly-crystalline channel, the number of stacked cells along with a bitline, and the configuration of the multilevel cell. The simulation data show that the temperature change was smaller than 3 K under read operation; therefore, SHEs are no longer a concern for advances in 3-D V- NAND flash memory technology. In addition, we investigated whether SHEs are influenced by a thermally isolated channel, as in a novel architecture named peripheral-under-cell (PUC), which is a peripheral circuit under cell for 3-D V- NAND flash memory.