3-D Channel Structure Flash Having Short Channel Effect Immunity and Low Random Telegraph Signal Noise

We suggest a 3-D channel structure flash named Lambda-like active profile cell (Lambda cell), aiming to archive good short channel immunity, high on-cell current and lower random telegraph signal (RTS). The results show that 'Lambda' cell has more channel punch-through margin and higher on-cell current than that of normal planar cell. Especially, the RTS current fluctuation of 'Lambda' cell was reduced from 4% to 1.2% in comparing with planar cell due to enlarged active area and lower channel doping concentration. These advantages of 'Lambda' cell make it a promising structure for the continuous scaling of the NOR flash memories to 45 nm and beyond.