The Effect of Fixed Oxide Charge in Al[sub 2]O[sub 3] Blocking Dielectric on Memory Properties of Charge Trap Flash Memory Devices

In this article, we report the effect of fixed oxide charge in Al 2 O 3 blocking dielectric on memory properties of charge trap flash memory devices using Fowler–Nordheim program/erase mode. It was found that negative fixed oxide charges in the Al 2 O 3 dielectric play a crucial role in improving erase efficiency of Al 2 O 3 ∕ SiN ∕ SiO 2 (ANO) stacks, and thus reinforces the advantages of a Al 2 O 3 blocking layer for charge trap flash devices. Compared to n + poly - Si ∕ ONO stack, process-optimized ANO stack with high work-function metal gate shows dramatic improvements in retention vs minimum erase state.