Effects of the interaction of neighboring structures on the Latch-up behavior of C-MOS ICs

An experimental investigation on the interaction between different parasitic devices in CMOS ICs from the point of view of latchup triggering is outlined. The study, carried out by means of ad hoc test structures, shows that this interaction: (a) can lead to significant increase in latchup susceptibility; (b) can involve devices very distant from one another; and (c) is not always suppressed by guard ring protections. The main features of the experimental results are discussed and explained