Transient-induced latchup dependence on power-pin damping frequency and damping factor in CMOS integrated circuits

Abstract

The bipolar (underdamped sinusoidal) transient noise on power pins of CMOS integrated circuits (ICs) can trigger latchup in CMOS ICs under system-level electrostatic-discharge test. Two dominant parameters of bipolar transient noise-damping frequency and damping factor-strongly depend on system shielding, board-level noise filter, chip-/board-level layout, etc. The transient-induced-latchup (TLU) dependence on power-pin damping frequency and damping factor was characterized by device simulation and verified by experimental measurement. From the simulation results, bipolar-trigger waveforms with damping frequencies of several tens of megahertz can trigger the TLU.most easily. However, TLU is less sensitive to the bipolar-trigger waveforms with an excessively large damping factor or an excessively low/high damping frequency. The simulation results have been experimentally verified with the silicon-controlled-rectifier (SCR) test structures that are fabricated in a 0.25-mu m CMOS technology.