On-chip ESD protection in dual voltage CMOS

摘要

In a split gate process for dual voltage chips, the N-type high-voltage transistors which are part of the ESD protection circuit, and therefore have the thicker gate oxide of the high-voltage transistors, can receive channel doping and drain extender doping which is the same as the core transistors. This causes these transistors to develop a high substrate current during an ESD event, triggering the protection circuit.