Optimization of Programming Pulse Shape for Vertical NAND Flash Memory Using Neural Networks
Sungho Park, Jaehyeon Kim, Jonghyun Ko, Jiseong Im, Yeongheon Yang, Jae‐Joon Kim, Jong‐Ho Lee · IEEE Electron Device Letters · 2024
We optimize the shape of the pulse to maximally increase threshold voltage (${V}_{\text {th}}\text {)}$during the incremental step pulse programming (ISPP) of vertical NAND (V-NAND) flash memory using neural networks (NNs). NN is trained using data on the increase in${V}_{\text {th}}$of commercial V-NAND flash memory in response to randomly shaped programming pulses (PPs). The trained NN is utilized to optimize the shape of the PP. The principle behind the improvement in${V}_{\text {th}}$increase due to the optimized PP, as well as the improvement results, are confirmed through measurements. When the optimized PP is applied to ISPP operation, it results in a 37% increase in ISPP slope. Furthermore, the optimized PP exhibits lower program disturbance, indicating the potential for faster programming with lower energy consumption.