Investigation of Switching-Induced Local Defects in Oxide-Based CBRAM Using Expanded Analytical Model of TDDB

The degradation behavior of Ag/SiO
₂
-based conductive bridging RAM (CBRAM) is analyzed by conventional and expanded time-dependent dielectric breakdown (TDDB) models. By comparing the total cycling stress with time-to-breakdown (t
_bd
) of the SiO
₂
used as a solid electrolyte switching layer, it is clarified that the cycling stress does not reach the level at which dielectric breakdown of the SiO
₂
is triggered. On the other hand, we found that the t
_bd
distribution after several cycles of set/reset stress agrees well with the simulated t
_bd
distribution derived from expanded TDDB models, in which we assumed that a large amount of defects exists locally in the device area. This approach is useful for understanding the degradation in solid-electrolyte oxide of CBRAM.