Failure analysis on gate-driven ESD clamp circuit after TLP stresses of different voltage steps in a 16-V CMOS process

The ESD robustness of gate-driven ESD clamp circuit in a 16-V CMOS process was investigated by the stresses of transmission line pulse (TLP), human-body-model ESD test, and machine-model (MM) ESD test. After TLP stresses of different voltage steps, the same ESD clamp circuit got different secondary breakdown currents (It2). In order to understand such unusual phenomenon, the failure analysis on the TLP-stressed ESD clamp circuits was performed to find the failure mechanism.