ESD characterization of multi-finger RF nMOSFET transistors by TLP and transient interferometric mapping technique

The ESD robustness of multi-finger nMOSFET transistors in an advanced RF CMOS technology has been analysed by both TLP and, for the first time, by transient interferometric mapping (TIM) technique. Failure current It2 has been studied for different source, gate and bulk contact grounding configurations, for TLP pulse duration between 25 ns and 550 ns and TLP rise time of 1 ns and 10 ns. The lateral distribution of dissipated thermal energy during a TLP pulse has been measured by TIM. The ESD failures for selected pad configurations are investigated by DC-IV and physical failure analysis. The highest (lowest) It2 has been revealed for floating (grounded) gate and bulk pads, and attributed to the pn junction (gate oxide) damage.