Dependences of damping frequency and damping factor of bi-polar trigger waveforms on transient-induced latchup

The dependences of damping frequency and damping factor of bi-polar trigger waveforms on transient-induced latchup (TLU) were characterized by device simulation and verified by experimental measurement. From the simulation results, the bi-polar trigger waveform with damping frequency of several tens of megahertz can trigger on TLU most easily. But, TLU is less sensitive to bi-polar trigger waveforms with an excessively large damping factor, an excessively high damping frequency, or an excessively low damping frequency. The simulation results have been experimentally verified with the silicon controlled rectifier (SCR) test structures fabricated in a 0.25-mum CMOS technology.