A Critical Failure Source in 65nm-MLC NOR Flash Memory Incorporating Co-Salicidation Process

Sporadic drain disturb problem in multi-level cell (MLC) NOR flash memory devices incorporating cobalt salicidation processes becomes a new critical failure mode. The provoked disturb is shown to be caused by erratic lateral encroachment of cobalt salicidation on the drain region of the flash cell. This failure becomes increasingly significant as the device cell size is scaled down. In this work, we report our study on the new failure mechanism and suggest our engineered device fabrication method to alleviate the cobalt encroachment