Analysis of TPA Pulsed-Laser-Induced Single-Event Latchup Sensitive-Area

Two-photon absorption (TPA) pulsed-laser testing is used to analyze the TPA-induced single-event latchup sensitive-area of a specially designed test structure. This method takes into account the existence of an onset region in which the probability of triggering latchup transits between 0 and 1 as the laser pulse energy increases. This variability is attributed to a combination of laser pulse-to-pulse variability and variations in local carrier density and temperature. For each spatial position, the latchup probability associated with a given energy is calculated. Calculation of latchup cross section at lower laser energies, relative to onset, is improved significantly by taking into account the full probability distribution. The transition from low probability of latchup to high probability is more abrupt near the source contacts than for surrounding areas.