In Depth Analysis of Post-Program VT Instability after Electrical Stress in 3D SONOS Memories

Abstract

Through Post-Program-Discharge measurements we achieve in-depth understanding of the ONO stack degradation observed in 3D SONOS memories that results in VT instabilities after the program pulse. We demonstrate that hole injection during erase is degrading the Tunnel Oxide, leading to formation of defects, that can be charged during program but emit electrons soon after. Through device simulations, we could also achieve a precise profiling in space and energy of these stress-generated SiO2 defects and develop a complete model of charge loss in degraded devices.