A Novel Structure for Beyond-45 nm NOR Flash Technology Featuring Short Channel Effect Immunity and Low Random Telegraph Signal Noise

Abstract

We proposed a three-dimensional (3D) flash structure named recessed channel array transistor (RCAT), aiming to archive good short channel immunity and lower random telegraph signal (RTS). The results show that RCAT cell can keep a 110 nm effective gate length and consequently a punch-through voltage above 5 V even in 45 nm technology node. In RCAT cell, the RTS Vth variation was reduced from 0.5 to 0.2 V compared with planar cell due to enlarged gate length and lower channel dopant concentration. These advantages of RCAT cell make it a promising structure for the continuous scaling of the NOR flash memories to 45 nm and beyond.