Non-linear width scaling of ESD protection devices and link with p-well implant in BCD-processes

In the transfer of a BCD-process, large differences in width scaling were found in ESD protection structures. Investigation showed that the presence of a ΔVthΔVth-implant was the root cause for the non-linear relationship between device width and soft fail current. The devices also showed large differences in leakage currents. In this paper an explanation is given for both phenomena: from a theoretical point of view and based on TCAD simulations.