Tunnel Oxide and ETOXtm Flash Scaling Limitation

摘要: Intrinsic tunnel oxide thickness limit is around 6 nm due to direct tunneling. In practical devices, the 8 stress induced leakage after program and erase cycles. Nitridation reduces electron trapping but does not decrease lower limit. Operating voltages also do scale well in flash memories. Voltages required for operation range from 1012V channel hot stacked gate devices up 20V Fowler Nordheim devices. This places transistor isolation scaling. Looking ahead, cell scaling beyond 0.13 p will be difficult unless there major breakthrough. Multi level storage technology provides a cost effective alternative process Feasibility studies showed that 16 levels or 4 bit per possible with gate. Stacked memory using programming best suited high density multi technology.