Latchup and the domino effect

CMOS latchup can be initiated in semiconductor chips from minority carrier injection sources. Injection sources occur from both circuit, chip and system level phenomena as well as single event particles. The paper discusses the problem of external CMOS latchup from minority carrier injection in a substrate region, and the initiation of CMOS latchup in integrated circuits. The paper proposes an analytical model to address the injection from a primary injection source, the CMOS latchup stability condition of a circuit from the primary injection source, and the successive propagation of CMOS latchup in adjacent circuitry initiated by the primary source and subsequent secondary injections. The focus is on the physical understanding, and the analytical development for quantification of the external latchup problem.